I think it's true that some shops have a similar mindset to scalpers in that they set exorbitant prices that people are willing to pay in person when they can see something, but less likely to pay over the Internet. Shops have a certain amount of legitimacy for people psychologically compared to an individual, particularly selling through the net. But doesn't that just make it legalised extortion? Maybe some people know they are buying things that they could get cheaper, but they simply can't wait to get it through the post - impulse buying. I think some shops really capitalise on that.