To paraphrase Mark Twain - all it takes to get people to want something is to make it rare.
Fifty years ago, kids put trading/sports cards in their bike spokes and checked the lists with pens. Today trading cards are an entirely speculator driven hobby from bottom to top - foil variants, foil packs preventing resealing, beckett grading, et al. That entire industry revolves around the introduction of artificial scarcity, because old cards became scarce and business oriented collectors and investors moved in.
Trading cards are a fairly monolithic hobby because they serve no practical purpose and they are made of common, nearly worthless materials. They are only driven by speculation and scarcity, little more. They're intended as a marketing tool for sports leagues. They're an effective vehicle for money laundering and wealth transfers. Observe what is happening to the retro boxed console games market now.
Retrocomputing is a much more complex hobby because it has a greater historical impact, was not built around collecting and trading from the start, requires much greater technical understanding and skill to be proficient in, and introducing artificial scarcity into modern computing isn't a viable business model to operate on. NVidia and AMD would much prefer to sell a billion GPUs they make $50 apiece on than 100 million they make $500 on, because it's better for their taxes, keeps more people retained, and keeps more users/companies/VARs tied into their ecosystem with contracts and sponsorships. Computer equipment is made of materials which have an ever-increasing scarcity and raw value. It's unlikely you'll see some grading company putting Gravis cards in lucite, or ebay listings mentioning "foxing around the edges" of Voodoo 2s.
As hobbies go there's tons of valid reasons for everyone involved to participate in this hobby, and that's why I say there's no "right" way to go about it. Some people care more about speculation, some care about preservation, some care about access. All of these tie into one another. Speculation drives interest which keeps things out of landfill or from being melted down for component metals. How many Voodoo 5 5500s or GUS cards or whatever holy grail which are available in the market to purchase, are only available because someone who had one was made aware it was desirable, so sold it instead of tossing it out? What's better, more interest and more available hardware that's more expensive, or less interest and hardware that's cheaper, but more scarce? The latter cannot math out - if it's scarce and sought after, it will rise in market value and drive speculation. This is just basic economics. One can reminisce over the 70s-80s hobbyist days all they like, but during that time the hobby was small and the vast majority of old equipment was being literally shredded or sent to landfill by companies as there was low demand for it.
As there is no "right" way to go about things, there's also no "wrong". If the ebay prices are too high, don't pay them. Build your own Snark Barkers or other replica cards and homebrew systems. Emulate. Do what thou wilt. But grumbling over the prices or people carving out an income or operating a business surrounding the hobby and equipment, won't do a thing to change it. Like the computing industry, things change and grow in the hobby surrounding it. It's called a "hobby industry" now, and that's a genie you can't put back in the metaphorical bottle.
- If making money is your goal, you win because the industry has shifted in a way that makes doing so viable, your collection is now worth more money, even if YOU don't choose to profit from it.
- If preservation is your goal, less equipment and "lost treasures" end up in landfill, so you win even if YOU aren't getting to be the preservationist.
- If getting to play with the equipment is your goal, more of it ends up at meets and shows for you to play with as a result of this, and more gets documented and emulated, so you win even if YOU don't get to have the actual computer in your house.
- And if introducing new people to computing or spawning a new generation of programmers/engineers/whatever is your goal, all of the above accomplish this, so you win unless YOU don't like that.
No matter how you spin it, you win unless you wanted things to stay the way they were back in the day where YOU got to have all the toys, and everything involving computing was gatekept as arcane wizardry that laypeople could naught comprehend.
The hobby and industry are infinitely more accessible today than they were 20-30 years ago, the only thing that's declined along the way is insular hobby communities and groups. And those do have a charm and feel to them which I can understand, but the entire Internet is the same way. 30 years ago the Internet was only accessible to people in select western countries, was populated by about 95% men, who were by and large mostly white. Today that is not the case. This hobby also had the same problem, and its growth changes that. This is nothing but a good thing, and if speculation helps drive that change, so be it.