gta is not exactly a trademark..GTA could mean any damn thing...infact GTA itself means Grand Theft Auto, and that is the name of a crime, not a game
considering that GTA is probably the most successful game after Sims and WoW, and the GTA4 launching soon, this could be worth about 10k+ (or a lot more)
Jew.us sold for 30k
and GTA has revenues of several hundred million...