Microtek C586p 15" LCD monitor, with VGA output only. 1024x768. It makes a nice secondary monitor, although it might be slightly dim in comparison to other LCDs. It's got a scratch on its gray border but that's purely cosmetic. $75 OBO.
Kingston 512MB DDR333 (PC2700) SDRAM of which I have two. They're fine sticks of RAM which have served me well for a few years. I recently memtested them and they're completely fine. Great supplementary RAM for any desktop that's a few years old or more. $40 each OBO.
AMD Athlon XP 2600+. A great upgrade for any slower Athlon XP, and it works fine. Still is fine for day-to-day use, and even lets you play modern games pretty well. $50 OBO.
ASUS nVidia GeForce4 MX 4000. An utterly baseline AGP video card with 64MB VRAM, but has DVI, VGA, and composite video output - so if you're looking for dual display action, here's your ticket. I bought it as a cheap replacement, and unless you're doing anything related to gaming or other high-end stuff, it's a nice step above integrated video for older computers. $10 OBO.
Generic GeForce4 MX 4000. A video card I got back in 2003. Works fine. AGP, 128MB VRAM, with DVI, VGA, and S-Video output. Why was I using the previous card instead? Because I thought this one was broken, but it turns out it was my motherboard that was (which, of course, I am not selling). Although quite baseline it's got more video memory, so it might be slightly more suited for gaming, etc. $20 OBO.
Thermaltake Polo735 heatsink and fan. It's utterly massive but gets the job done, with a dense copper base and a very strong fan. Has a temp sensor, but also comes with a knob that can be attached to your case's 2.5" (floppy) port to manually control it - that's what I did, because it can get pretty loud cooling down an Athlon XP 2600+. Can mount onto K7, K8, and P4 systems, from what I can tell. $20 OBO.
If you're local (Bay Area), I will help install any of these components for an extra $5 to $10. If you're not local, we can talk about shipping, etc.