well - i have to say - if their customers are stupid enough to think that the games actually came in those plastic cases as retail, and that they don't notice them being 'factory sealed' right in front of them then it's their own fault. If on the other hand they fully realise, and are just too lazy to buy cases, print our covers and source the cart, then i see no problem with them paying for the benefit of someone else doing it.
If there weren't people buying them, the store would stop selling them, simples.
Whilst i wouldn't say i wholly agreed with it, and it would be nice to claw back some cash for site running costs/development, but i don't have a problem with the supply/demand thing here really.