There are for sure certain sound cards, video cards, etc that people want, even mice and keyboards. Certain Macs will catch at least a few hundred but %99.99 of all PC hardware is literally just garbage, even most of the gamer shit. Earlier home computers like certain MSXs, Commodores, NECs, are probably worth more than almost anything than ever ran Windows XP. I'd suspect SGI's are still worth money to collectors even though they have no use anymore but those aren't really "PCs" exactly. I've never seen one run a game, it was always Maya or something. Some PC gear gains value just because it has some legacy use and there isn't a current replacement but this isn't due to any collectardation.
Compare this to Neo home cart prices...no contest. The Neo is the only system where if you bought every game ever made as they came out new you actually would have made money.