Like photon said, Early April there is supposed to be a price drop in processors. Wait till then for sure to see what it looks like.
My post will probably skew more toward the gaming side, since thats what I do. You may want to consider different video cards and processors if you're into more editing than games.
Compare memory express with
www.ncix.com
Memory express won't price match NCIX, but you may find that NCIX is cheaper on some things. Their based out of Vancouver, their shipping rates are reasonable and they are super fast. I'm talking 1 or 2 day shipping.
When I build my rigs, I use a combination of parts from those two places. Oem depot right across from mem express on the other side of macleod trail might also be worth checking out if their still there...haven't been there in a while. They don't have the selection or service, but if you want parts, it's pretty much the cheapest place i've found.
http://www.oemdepot.com/index.asp
You can get a pretty decent setup since you've already got a few parts.
Best PSU money can buy is PC Power and Cooling. But their expensive. Don't skimp on PSU though. A lot of people buy the $30 ones which later fail. Get a half way decent one by a major manufacturer. Silverstone, Antec etc.
PSU - $113
http://www.ncix.com/products/index.p...ufacture=ANTEC
You might want more power if you plan on doing SLI or Crossfire, but with your budget, you probably don't want to spend $1000 on video cards.
I like AMD.
Processor - $303
http://www.ncix.com/products/index.php?sku=18453&vpn=ADA5200CSBOX&manufacture=A MD
Motherboard - $125
http://www.ncix.com/products/index.p...nufacture=ASUS
or if you want SLI capable board for the future:
http://www.ncix.com/products/index.p...nufacture=ASUS
Video Card - ~$400 if you want a DX 10 card. I would only buy DX 10 now because if this rig is expected to last any length of time new games coming out will want SM3.0 at least and you get the benefit of what dx 10 can do.
http://www.ncix.com/products/index.php?sku=21406&vpn=640-P2-N821-AR&manufacture=eVGA
http://www.ncix.com/products/index.p...anufacture=XFX
I personally don't think you need to spend $150-$200 on a sound card, Buying a $200 sound car when you have crappy speakers isn't going to do much good. Buy at the level of your speakers.
So that's a grand right there. But you're going to need ram at $200-300. More if you want more than 2 gb.
Optical drive, HHD unless your using your old stuff.
If $1000 is too much for those parts, you can probably find a tuned down 8800 for cheaper, and find a lower processor.
ATI's R600 series are supposed to be coming out soon. Those are ATI's DX 10 cards. Might want to wait to see what they have to offer.