Buying Factions via CD Key?

I'm interested in buying Factions (last GW game I don't have), but I'm quite strapped for cash at the moment.

Anyone bought a key through the Offgamers website? Is this a valid method to obtaining Factions? Looks legit to me, just wanna make sure.

EDIT:
Went ahead with it and it worked.

Please lock.

Didn't I talk to you ingame a few hours back?

Closed at OP's request