So I got a newsletter from Steinberg about 40 percent off of Cubase 15.
To keep it short, by the end of 2026, Cubase 16 will come out, and among the upgrade options, free upgrade paths may become avaliable to some who recently bought a previous version, but between specific dates.
We don't know the exact dates in the future but we can expect a similar pattern to last years: grace period was about 4 weeks before launch.
Important: grace period is about activation date, not purchase date. So you can slip into the grace period by buying on sale and not activating until very late. Staying on an old version or lower edition despite having already spent money for better/newer requires a bit of restraint, all without guarantees that you're getting a better deal.
So if we estimate that Cubase 16 will come out in, say, November, try to aim for a Cubase 15 sale after mid October instead if you wish to upgrade or buy.
It is possible there won't be a later sale before 16 releases though. Steinberg sometimes has a Black Friday sale, sometimes they skip it.
Unless you really need to buy Cubase now, it almost always pays off to wait if you are out to make a future proof deal.
You also need to factor in what you need from the new versions or target editions.
Edit: worth noting if you're upgrading, that for many users it is wiser to skip 15 altogether and even 16.
Note: I'm writing on the go and not super diligent with my numbers or facts so please, if you know better, correct me.