How to spend coins

Hello everyone, I've been playing on Molten cata server, but stoped before all that moltdown happened or whatever it's called, decided to play again on MoP server, restored account and have 25 coins now, apparently it can buy me some weapon or something, I was pretty casual pvp player, doing bgs, duels and arenas occasionally, but nothing too serious, and plan to do the same now, so the question is what class will benefit most from something I can buy with these coins, sorry if this question is stupid and for bad english, thank you :)