I don't use Prime and have noticed Amazon keep increasing the time taken for 'free delivery' to a point where i'll just buy it from eBay now, or direct from the retailer.
My current complaint about Amazon is that when I order a grocery item, it's because I can't find it in a local store and Amazon charges double or triple the normal price.
Oddly enough, I ordered something once in bulk for an exorbitant price, and immediately it appeared in my local grocery store for the normal price (50% less). I'm not sure what's going on, but it feels like algorithms run amuck.