If the assholes who were hording the PS3s weren't selling them, there would be plenty for people who actually wanted them. So no, it's not perfectly ok. It's taking advantage of others, and a pretty shitty thing to do.
You go ahead and let me know when Wii accessories start selling on eBay for double their retail value. Selling Wii accessories is retarded, and it's a waste of time.
You can't find Wii-motes or nunchuck's anywhere around here b/c people like this douche come in and buy them out to try and resell on ebay for a profit. Oh well, I'd rather wait weeks to get another remote and nunchuck then buy one off ebay.