As with any vintage item you never really know where the value is going to go. "Vintage" PCs are probably getting rarer and rarer as people continue throwing them out. I actually had no idea they would even go for $150-200 right now. I never see the estate sale "regulars" here take a second look at any computers but I'm sure they will start to wise up soon enough for that price. And yes their are estate sale regulars, if you go to more than a few you will start seeing the same people over and over again. I've met people who've bought and resold things at estate sales for all their working lives.