And you know what Sony sells them for.. how? When you go to gamestop (or any other store) PS4s and PS4 Pros are sold at full MSRP. "Suggested Retail Price", not Minimum Advertised Price, or anything of the like. I guarantee stores get them cheaper than MSRP, or else they'd never sell any.
This is the same premise of massdrop. Buy enough items in bulk for a better deal, just like a store would. Except it's consumers saving money, not the stores.