Great to hear about another Linux user added to the numbers!
For those who are looking for free computers (no selling allowed), find your local freecycle group, join & see what's there, or post what you're looking for. Many gives away XP computers just to get these out of the house.
Dell Dimension 3000 Desktop in Good Condition $50
That's not an unusual asking price for that computer around here either, unlike the very mass produced Dimension 2400, these has a better MB, more upgrade options as to CPU, and components are plentiful & low cost on eBay. Not that I'd purchase one at this point, but if in good shape, not totally unreasonable.