Amazon doesn't have any extra power post-local stores. If Amazon ups their prices then the local stores reappear. In some weird future where Amazon completely obliterates small businesses it might take a few years, but it'd take more than a few years of good prices before that from Amazon to get to that state. The manufacturers always have strong incentives to defect from an AWS dominated equilibrium. They want middleman prices to be low, it means they move more goods and make more money.
Although I should stress I like the idea of buying local. If the money goes off to some exotic foreign place it is less likely that I will get my hands on it later on. Better to live in a wealthy community than a poor one, etc. Local capital is local prosperity.
