I can sell you my old IBM PC @4.77mhz with 512KB! ram for 1.000 euro. If your cheap P2 400 isnt working...
your old IBM would be worth more than that dude, dont get rid of it, its an antique!
But seriously, go to the back of any computer shop, they often throw away much better stuff than that in working condition, we do all the time at work, Pentium 4's all over the place, full working systems.