First of all, IANAL: An email asking how much of a salary drop it would take to drop the non compete (thus giving Amazon the chance to negotiate) and them repl

First of all, IANAL: An email asking how much of a salary drop it would take to drop the non compete (thus giving Amazon the chance to negotiate) and them replying with "its non-negotiable" should go quite far, the problem is you have to wait until Amazon sues you to actually see if it'll work. Your best bet would be to retain a lawyer as soon as you get an offer and tell him to do his best to get you out of the non compete, and the legal strategy will vary greatly depending on the state in which you are being hired.