I could have sworn I just paid a couple hundred for some corsair xm2. Looking at the prices on newegg.com today it seems really cheap for 2gigs. 73 bucks with rebate. What's going on?

http://www.newegg.com/Store/Category.aspx?Category=17&name=Memory

DDR3 is released and Intel is hell bent on getting it out on the market despite it's rediculous prize and marginal performance improvement.

Well I realized that the ram I have was a little more than the stuff I saw - xm2 dominator. This Cheap Ram! (http://www.newegg.com/Product/Product.aspx?Item=N82E16820145034) seems like a good deal at 73.00 for 2 gigs. Worth getting I'm assuming? Would put me at 4 which is the cap for XP I believe.

Be careful about speeds. There's a pretty massive difference between slow and fast RAM of the same variety. You're often better off with a smaller amount of fast RAM than a large amount of slower.

Well, it depends how much memory you intend to use, of course (and how often). Slow RAM is still orders of magnitude faster than using swap space.

Where you really want to be careful is the reliability of your RAM. Tiny errors can quietly corrupt your data and cause mysterious crashes. If you go with cheap RAM, consider testing it on a regular basis, using something like memtest86.

I have this (http://www.newegg.com/Product/Product.asp?Item=N82E16820145168). I think I'll probably just get another 2 gigs of it unless someone says otherwise.

I have Corsair in one of my machines (2 gig PC3200) and it works great. I would say go ahead and get matching ram. I know people who have had issues mixing ram, always good to try to have it all the same, can't hurt.