I don't see the issue even if ocuk weren't charging the same prices, at the end of the day it is the going rate for 480s etc. now so people are perfectly entitled to list "their" product for that price too.
It would be a bit different if someone bought 3+ from somewhere and then came on here to sell them all for the much higher price but that isn't happening from what I can see.
EDIT:
Heck even gibbo himself is encouraging everyone to sell their 480s, 290s, 390s etc. etc. for silly prices.....
It's in the MM rules that you can't sell something for more than you bought it for. Personally I don't care either way, but rules is rules ;o