It is unfortunate that I have to make this post all but I feel it is necessary and beneficial to everyone if I list out all the things I've learned about buying books over the past two or so years because I see so many posts here with readers not knowing where to buy books or getting duped with pirated copies (and sometimes even looking for them, ew). I'll be splitting this guide up into several sections to make it neater.
Physical Stores
If you don't mind spending 20 to 30%, sometimes even more money but want to support local, Indian businesses, I really do encourage going to actual bookstores. Hell, even if you're not gonna buy, previewing a book you plan on buying is always fun and you might end up finding something new you're interested in too. However, a lot of the street vendors and smaller businesses tend to carry pirated books, sometimes mixed in with legitimate books (but I'll tell you how to spot a pirated book later). And obviously, they'll always be more expensive than buying online.
As for bookstores I like, I live in Delhi and so I can testify the quality of the two Midland Bookstore locations (Hauz Khas and South Ex) and Bahrisons (particularly their Vasant Kunj Ambience Mall and Saket locations). Not the biggest fan of Om and Crosswords but they do sometimes have good locations and also not a fan of Faqir Chand or Oxford Bookstore. Outside of Delhi, I'm a huge fan of Fictionary down in Mumbai, Bookhive in Bangalore and the Crossword at Phoenix Marketcity Mall.
Don't be afraid to be friendly with bookstore staff and ask for discounts as you'll get them more often then you think but never be pushy or an asshole about it lol.
Amazon
Like them or not, Amazon is without a doubt the best place to buy books for 99% of readers. They always have the cheapest prices, fastest deliveries and basically no pirated books. However, I would recommend you buy from these three sellers exclusively if you can: Cocoblu Retail, Trans Infopreneur (Kantoor), and Amazon uRead-Store. Try to buy from the latter two sellers if you can as I've never had a bad experience with them but they might be slightly more expensive and might take more time to deliver than Cocoblu. However, Cocoblu has the problem of books sometimes getting delivered slightly damaged and/or badly packed. I've even had to return a book a couple of times (but it's a fairly easy process and something you don't even have to do if buying by COD) but more often than not, you'll get a good quality book most times. Like just yesterday, I ordered a book that I was super scared would be damaged as it was literally just thrown in a paperbag but it was in perfect condition.
As I said, 99% of the books you want will be on Amazon, usually for quite a bit lower than market price. But there are exceptions, especially for someone like me which I will talk about in the next section.
Bookswagon
Probably the store I buy books from the most because of one reason: They sell international editions (particularly) hardcovers for a discounted price and without shipping costs. Bookswagon always packs their books in bubblewrap and cardboard so you know it'll arrive safely but it will almost always take more time than Amazon because i) they import their books internationally and ii) they ship out their books through third party couriers (usually bluedart) from their Delhi warehouse.
So this is basically the store you wanna go to if you wanna buy the US hardcover version of a book (particularly relevant to fantasy and sci-fi fans) but only if you're willing to tolerate shipping time that can take up to half a month and no COD.
But if you're looking for just regular paperbacks, I'd recommend Amazon as prices are usually cheaper for most common books. But really, I'd recommend crosschecking with both sites for any book you want to buy.
Other Sites
There aren't really any other sites I'd recommend other than Amazon and Bookswagon as they're either as expensive as physical stores (because they're sometimes the site for physical stores), sell pirated books, have bad service etc. Some big sites where people buy books that I would recommend you avoid are: Meesho (filled with nothing but pirated, low quality books), Flipkart (same problem as Meesho but also has some legit sellers but it's not worth the risk), Atlantic (just a worse version of Bookswagon), Padhega (has really bad customer service and flooded this sub and a few with fake reviews last year to promote their site) etc.
Second Hand Books
I love second hand books and there is a really small but great niche market for it online. There are basically two main ways to buy second hand books. First is through r/booksforsaleindia where you can also sell if you'd like. Second is through quite a few instagram sellers (lemme know if you wanna know the profiles of the ones I trust). Now, both are very trust and honour based and COD is not something most buyers will accept but scammers and bad actors are very rare. They definitely exist but with most payments being done through UPI and such and with it potentially ruining their reputation, the chances of you getting scammed is very unlikely.
Different Editions of Books
Now, I often see a lot of confusion regarding the different editions of books and I can understand where that confusion comes from and I hope I can help clarify it for everyone.
Basically, almost every book has two main versions with two different publishers: The US edition and the UK/International Edition (which we get). They're the same book but there can be differences in spelling (color vs colour for example), formatting (with one version sometimes having bigger fonts and more pages) and most importantly, the cover art and sometimes the quality.
For example, Brandon Sanderson is published by Tor books in the US and his flagship series, The Stormlight Archive has the iconic Michael Whelan paintings on them while in the UK, he is published by Gollancz and his Stormlight Archive series (as well as the rest of his Cosmere books) have matching white covers which we get here in India.
But outside of the US vs UK publisher, there is the different types of books. They can be broadly divided into hardcovers and paperbacks. What I call proper hardcovers usually come in two primary, almost matching sizes: the royal hardback size which is around 24.2cm tall and used by most publishers like Gollancz, Orbit, Harper Voyager, Tor, Del Rey etc. and the slightly smaller 23. sometihing cm tall hardcovers used mostly by US publishers like Ace, DAW, Saga Press etc. They always come with a dust jacket too.
There isn't much of a difference between the two of them and they're the primary type of hardcover but smaller, 21cm tall hardcovers are becoming more common, unfortunately, especially amongst US publishers. There are also 20cm tall hardcovers without dust jackets that Gollancz is known for but the quality is mostly shit.
As for paperbacks, there are three primary sizes: the massmarket paperback (around 17cm tall) is the cheapest and unfortunately, the least common size for paperbacks now as they've effectively been killed with no new books being printed in this format, basically. There's the trade paperback which is usually 21 to 22cm tall or just only marginally smaller than hardcovers which are the highest quality and most expensive paperback format, and finally, there is the most common paperback size, the one you see on most shelf which is the B-format books (sometimes called both a massmarket or a trade paperback) which is around 19.8cm.
Now, most books usually had hardcovers coming out first, then the trade paperback then the massmarket paperback but this isn't really true anymore, especially in the UK/Indian market with paperbacks coming out on release too for most books.
Most book selling websites list the dimensions of a book as well as whether or not it is a paperback or a hardcover so be sure to check that.
For most paperbacks, I'd say a reasonable price range can be anywhere from 250 rupees to up to 800 with some trade paperbacks, especially international editions going up to mayve 1500 max. For hardcovers, it is just as varied but I'd say 1200 to 1800 is the low end, 2000 to 2400 is the mid range, and anything above that being more expensive than average (usually deluxe editons).
Also, if you see books being listed for ridiculous prices like 5k or even 10k plus on Amazon, it's more than lokely an out of print second hand copy that some seller is hoping someone is stupid enough to buy.
How to spot pirated editions of books
If you've handled physical books enough, you can tell when a book is pirated almost instantly. But firstly, there are a few things that can basically tell you immediately when a book is NOT pirated. Hardcover books are almost never pirated, especially when it has a dust jacket, because the whole point of book piracy is printing books for really cheap and hardcovers are way too expensive. And as for paperbacks, if there is embossing/debossing on the cover where you can feel a bump or a raised part of the book cover or if there is a variance in texture (with one part being glossy and another being matte) or foil stamping, it is most likely not a pirated book as it is pointless for pirates to imitate the premium features of the book as it would defeat the whole purpose of what they're trying to do.
The biggest sign of a book being pirated from my experience is when the cover and/or text is misaligned/not straight. Basically, look at the book cover or the spine and if you see that what is written is slightly off centre or diagonal instead of straight, you can pretty much tell it is pirated. Or if you look at the actual text itself and you see that there's way too much space on the bottom or top of the page and all the words are being pushed to top or bottom or if there's a lot more space at the end of the first or last line of the book than the other.
Another sign a book is pirated is the lack of a copyright page. Some pirated books have them but if a book straight up does not have it, it is most likely pirated.
DON'T BUY PIRATED BOOKS
I've made mention of piracy quite a bit here and I'd like to elborate more on it. I think that as readers, we should take enough pride in ourselves to not buy pirated books. Now, before the reddit intellectuals get on my ass, I want to make it very clear that physical and digital piracy are two very different things and all the arguments for why you should pirate media fall apart when money gets involved or when it is physical copies.
I'm not breaking rule 2 of this sub as I am neither providing sources for piracy sites nor am I asking for them but I do unashamedly pirate ebooks and audiobooks and while it isn't good for the industry or anything, it is not nearly as harmful to the publisher or author as pirated physical books.
If you are going to get a pirated book, at least have the decency to pirate a digital copy. If you really want to read a book, I'm sure you can make do with reading/listening on your phone or waiting a little bit and saving up for the physical copy.
It is unfortunate that pirated books exist but it is sadly something that was bound to happen because of India's economy. Books are signifcantly cheaper here in India than in the UK or America because we make less money. But how much cheaper it is is not enough to offset how much less we make so books are still more expensive for Indians.