Budgeting for books

So as the title suggests I want to know how people budget/ don’t go broke on this hobby.

I’m not into audio books and I am very lucky to work in a bookstore where I can get most trad published books at a discounted rate. However, most of the books on my tbr list are with smaller independent publishers and only available on Amazon. While I’m happy to pay to support writers, I don’t really want to support Amazon, and also I don’t have the budget for lots of £15-20 books every year.

That being said:

• Is there any other way to buy these books rather than on Amazon?
• Is there anywhere good to buy second hand books in the genre?
• How are u guys budgeting! Do u just use the library and splash out only on what you really want?
• Are most of these books available at libraries?

Thanks!!!!