Hard to say if you should wait, without knowing the actual prices you are seeing. My experience is that sometimes these sites have stale info. They price from their database, but when you go to buy, they actually check with the airline, and you get the dreaded "this price is no longer available" screen. If that is not the case and they are offering fares you can live with, go for it.

As kudzu mentioned, prices go up, prices go down. My threshold at this point would be if they were under $275 or so, I would buy, otherwise wait a bit. And if you buy and they go down, it happens, you can't expect to buy the cheapest ticket on every flight you take.