Check out your local electronics recycling centers. There is one near me that pays different amounts for processors, ram, PCBs, etc.
Sometimes the CPUs can be worth some money. Google the part number, find out what it is, then check completed listings on ebay. Sometimes you will luck out and get a CPU that is one of the faster models that fits that socket. I did that with an old Socket 754 Athlon 64 a couple months back and got almost $40 for the damn thing. People with shitty old motherboards like that will try to find the fastest thing that'll fit it as an upgrade.
The other thing you can do is, if you're sure it's a working part, list it on ebay at a fixed price 30-day auction. This especially works well with motherboards. Say somebody's critical workstation or simple server takes a crap. It's easier to swap an exact motherboard than it is to revamp the whole system in many cases. They will pay a premium in that case.
Same for hard drives. Even old hard drives can be worth money because people buy them to swap the controller onto an identical dead model. Scrap stuff as a last resort, honestly, or if you know it's bad.