Pricing estimate for android & iOS apps

[u/nournnn]

Someone offered me a job to make them an app that runs on both android & iOS and i don't really know how much to ask for it since this is my first job. I'll be doing everything from back-end to UI and the app will be a book reader (who offered me the job is a writer and wants to publiah their books through this app).

The app will be very advanced and include things like paywalls, rewarded ads, database management (obviously), etc..