you could buy the ags, see if its to your liking, wait till it goes up in price again then sell it if it wasn't your thing, then go for something else. if your looking for a nice gs its obv. the sgs or a bgs if you wana have a nice chunk of $ with you still.
Unless you pk with it you should either use the money to raise stats or get much better armor for training and killing-Making more money. Ags is definately gonna stay around 80M stable.
Depends on what items you got. I myself, would get an AGS for my zerker if I had the money, I belive it's kinda low now to. So, if you realy want one - get one.