Are old PC towers worth anything?

I'm curious, are old PC towers really worth anything these days? With technology advancing so rapidly, I'm wondering if they still hold any value. Are there any collectors out there who are interested in vintage computer hardware? Or could the parts inside still be useful for upgrades or repairs? I'd love to hear your thoughts on the matter. Are old PC towers a relic of the past, or do they still hold some form of monetary or sentimental worth?