I shop yard sales,all I find is scraper PCs,which I tear down & sell the parts on Ebay for gold recovery.I have not yet found a decent high end system with a good vid card
HDD platters,magnets & circuit boards are worth a few bucks,as are cd/dvd rom boards.PSU & cases I give to a scrap guy to get rid of,steel prices suck & aren't worth my time LOL
I check all the ram,cpu's,hdd,cd/dvd roms.If they work & are not too outdated,I hang on to them to build basic PCs for websurfing