I have also noticed that suppliers also overprice, so the store might get something at cost for $50, and they will sell it for $55; whereas another store will get them for $45, and that store will sell it for $49.This is why at least some stores keep high prices. Stores that sell based on brand and atmosphere and customer service (usually pretty stupid customer service) *cough*apple*cough* overprice like mad. Ever tried going into an expensive clothes store, I happen to know some people that work in these, markup is >50% its messed.
This is called bulk buying, in other words, the more one store buys from a supplier the better discount they get. It's to encourage bulk buys as from a supplier point of view, you want to move stock in volume, not little bits and pieces here and there which is time consuming for little return.
I don't understand what is wrong with this? Bulk buying often results in lower prices for consumers.
But I'm with you on the mark up some up market retailers provide. Despite buying in bulk, they still jack up the prices simply because they can. And the masses lap it up because it's a "big name" they can trust.