As the other poster said, save up for a New CPU and Motherboard. WoW is very CPU Dependent. If you plan on staying AMD, there's a bunch of a nice AMD FX chips on the market now. Stay away from anything that is Bulldozer. I'm a intel type of guy because their chips now a days are very strong. So it's your call. Satan said your video card currently could use an upgrade, which is true! But still you'll have a CPU throughput problem with your CPU rendering frames and all the wonderful stuff on your screen.
Just save up, don't eat out. Tell girlfriend/boyfriend etc.. to cook dinner. Watch movies at home.. Go out only 1x a week. Don't do drugs maybe 1x a week. You get my point! And you'll save up enough to have a good pc