You see it in a lot of ebay categories, there are a handful of sellers that sell stuff well above msrp. I think there are ebay users who assume that when they go to ebay, they get a deal, so if the category is empty and the only products available are above msrp, they sometimes buy it without researching.
I can't imagine there's a huge number that do.... but at the same time, there are a lot of overpriced items, so it must work at least sometimes.