memory is incredably cheap... especially for the older machines.
The issue is wether or not you can put it in.
My home desktop is a Dual 600, with 1 gb of ram... I'd put in more, but the board will only accept 4x256mb (which I bought at $25.00 each)
I'd put in 2 gb, but the board will not take it. If I upgrade the board, I'll need new procs... I may as well but the cheap 499.00 deal from Dell, and have more performance.
The issue is just keeping the mother-in-law happy... on crap that I don't want at home.
What I'm looking to do at home, is beef up a server in my closet and run Terminal services on it, which will let the kids surf and do reports, but little else.