If you give your cashier a 10% raise, then you have to recover another $1.50 / hour so you have to sell $121.50 / hour or $10.13 every 5 minutes. So a 10% wage increase for one employee translates to raising prices by 1.3%.
I don't know what the economics look like for a warehouse worker, but Amazon can afford it and the community Amazon is a part of will be better off.