AR vs. ????

I've argued long and hard with myself on this. I shoot a lot of IDPA and for a brief period played at local 3 gun (one of maybe two using iron sights). I bought the cheapest AR I could find at the time (an Olympic Arms Plinker for $480 plus shipping & transfer fees). I sold it when I needed the cash. I'm considering buying another, mainly because I'm afraid I won't be able to soon.

If I were in a combat zone, I'd stick with .308. For home defense, I'm sticking with my .45 or a 12guage. I'm considering the AR for shooting paper in local 3 gun matches & IDPA side mathces (I usually bum one) but still think I should just save up and buy the .308 (M1A Socom). Cost of ammo is another factor for me.

GregB