I ended up tossing a bunch of stuff, mostly 386s & older. The sellable stuff is all things I use, or could use in the near future, so there's still a whole bunch of idle equipment in there.
Could use in the near future is the key behind my packrattiness. Will I ever use the 4 computers' worth of 486 parts? It's not really worth my effort to test & package parts for sale, because the selling price is so low. However, I spent a lot of money on that stuff in the past 3+ years, and there's enough use in them to make me feel bad throwing them away. I also have shelves full of VGA monitors, because they're not really worth tossing in the dumpster, but I couldn't sell them for $5 online.
You may ask why I have so much crap - how did Derek end up with 7 VGA monitors? Well, I've always had 2-3 computers running at once, and every time I upgrade the parts get handed down to the next most powerful computer, and so on, until the least useful part ends up on the shelf. The logic is, "if it was useful up until I upgraded that other computer, how can it be useless now?" I think I attribute too much value to useless things. Potentiality doesn't equal value.