This is just my opinion, but if someone uses their time, energy and funds to search for things, maybe clean them and test them (and possibly repair them), then resell them and deal with customers, I don't care what they charge... no matter what it is.
EDIT: Leaving this here for posterity, but I realize this isn't an accurate comparison, I only half thought this through and typed it anyway... There are people (possibly many of you here) who make as much in a single work day as a retro PC reseller makes on a good MONTH. You'd likely be offended if someone told you that you should just work for less money so more people could make use of your services, even though SOME people will pay you a lot more.
People can buy low and sell high on the stock market, or do ANY kind of work that involves being opportunistic, or any kind of job that pays well and doesn't require long hours or a degree, and this is completely accepted (even encouraged!). But if someone has spent most of their life working with computers which are now considered "retro", they are apparently bad people if they take time away from watching television and use it to find PC parts they can resell for profit.
I really enjoy playing with old hardware, teaching others about it and looking for odd-ball items, but it most certainly isn't a necessity. I don't feel like anyone is being deprived if they can't afford to play Glide games on a Voodoo 5 5500. There are wrappers, emulators and other things that can very closely simulate 98% of what we do on this site (hence the name VOGONS). The most valuable PC items rarely provide any significant improvement over some other more common ones. Once people get obsessive about having 100% accuracy, period-correct builds, or having "that one thing" they had\wanted as a kid, it is no longer about experiencing computers as they once were... not even close! Back in the day, hardly anyone was this obsessive about WHAT HARDWARE they used. We all just got the best we could afford and enjoyed it for a year until it was obsolete and we did it again. If you think you need incredibly specific parts to enjoy this hobby (authentic voodoo 2 SLI, four different rare sound cards in one PC, etc), then it has turned into some kind of perfectionist obsession and is no longer a representation of what it was like to "compute" when this stuff was new. If you insist on doing things this way so that your built\collection is "perfect", it's only natural that you will have to either spend a lot of time searching or spend a bunch of money to pay someone ELSE who has spent the time to search.
The same goes for classic cars, baseball cards, stamps, coins... whatever.
A person isn't losing anything tangible if they never get to drive down the road in 1962 Ferrari 250 GTO without a Babe Ruth rookie card and an 1804 silver dollar in their pocket. Doesn't stop those from being worth absurd amounts of money to certain people.
Similarly, no matter how much time I put into this, I highly doubt I will ever own a Cyrix 586 133Mhz, a Voodoo 5 6000 or a boxed Adlib Gold... and it doesn't bother me a bit. Less rare items aren't somehow exempt from this illustration just because you want them. 🤣