What's wrong with your Amazon example? They don't charge as much (and that's partially because, while they're big and dominant, they're still not as big/dominant in that market)

You could consider using Galvix, which will connect with your billing system (including Stripe), fetch all the invoices and automatically prepare and file sales tax returns across each of the US states where you are legally required to file, all while providing you full control and visibility over the process. Galvix charges a flat fee of $75 per filed return, which can be considerably more affordable compared to paying a revenue share to other platforms (if tax compliance is the only reason you want to use these platforms).

Disclosure: I am a co-founder of Galvix.