Is there another good place to get out-of-print books? Or are you saying that for current books, a brick-and-mortar store is best, and for out-of-print, rolling the dice with Amazon is better than nothing?
I'd recommend abebooks.com. Everything I've received has been in great shape and since it is media mail shipping is free or at most a dollar (for normal sized books that it, I haven't bought text books).
I don't know if you realize, but abebooks are a wholly owned subsidiary of Amazon: https://www.abebooks.com/about -- so this is like protesting Facebook by setting up an Instagram account.