All the Unreal Tournament games were delisted and I tried to purchase them before the delisting but I kept receiving error messages when trying to complete the purchases on GOG and Steam. Both support teams only give copy pasted answers and did not assist in any way, shape or form. Where can I purchase these games legitimately? Every gray market site has the keys at $900 each.

Ebay?

Preferably a way that does not require having to purchase a dinosaur of a computer required to run the old discs. I have some but it's difficult to build a dinosaur that gets the system requirements just right for those old games. It's becoming difficult to purchase older PCs because someone started a rumor about being able to get gold from the circuitry so now every yard sale people want $500 for their old computers.

Sorry, that's the breaks. That's an unproduct, like ZZT.

And the Surreal Engine is in early days.

Well, it appears you have reached the Troll who guards the bridge. If you can't afford the toll, or are otherwise unwilling to pay it: to endulge in the verdent grass, little goat, you will have to take a certain risk by wading through the fierce river currents, or stay where you are and look on as other little goats enjoy their fill.

I don't know what you're smoking but where can I get some?

You don't need a dinosaur. All the games work out of the box on Windows 10. I have them all on discs - the Unreal Anthology (Unreal, Unreal Tournament, Unreal 2, UT 2004), UT 2003 box and UT 3 box. Unreal engine was actually made by competent people and it shows through the fact you can still easily play the games on modern Windows without many tweaks. There might be some issues with Unreal and Unreal Tournament, but fan patches exist to fix any issues, should you encounter any. Any game on Unreal Engine 2 and on works perfectly fine.

For discs, you only need a drive, which can be gotten very cheap, even external ones.

Ask Epic why they idiotically decided to remove them from digital storefronts.

Outside of Ebay, you're basically SOL.

Once you do manage to procure those games, there's various patches for their respective games:

https://www.oldunreal.com/downloads/unreal/oldunreal-patches/

https://xmpcommunity.com/ for Unreal 2

https://github.com/OldUnreal/UnrealTournamentPatches for Unreal Tournament '99

The used market. I've gotten most of them over the years for very cheap, sometimes even thrown in for free with other stuff. Just last week I got Unreal Championship 2 for first gen Xbox for about $10.

As others have said, you don't need to buy an old computer to play these games. All you need is an optical drive. I'm very happily playing Unreal Gold, UT 2004 and UT3 on my Windows 11 PC using my retail copies. If (for whatever reason) you built your PC without an optical drive in it (perhaps you needed ALL the SATA ports for SATA SSDs?) then you can get a USB DVD drive really, really cheaply from Amazon these days.

Maybe they have the belief, that scarcity will make them more iconic and more valuable.
It's probable that they have something planned ... something like remakes or remasters, and they want to ensure folk will buy them.

As much as I like the Unreal games, I'm not sure they share the same iconic status as the Quake or even Half-Life games. In a way, it is a bit like the band Uriah Heep never quite enjoying the iconic status of Deep Purple, Led Zeppelin and Black Sabbath ... personally they always have with me, but alas many others have always felt very differently.

That said, the Unreal games have no doubt fared a lot better than many other somewhat similar games from that era.

Kind of the fantastic underdog.

You're joking, right? The Unreal series of FPS-es are universally acknowledged as some of the most iconic FPS-es of all time!

You have to bribe someone at Epic to relist those games and then you can support GOG by completing your purchase here.

Yeah. The first Unreal is only what, one of the most important milestones in FPS games' history? Obviously not iconic enough :D

Although it is true that Quake was generally more popular/known than the Unreal Tournament games. Never understood why, but most likely because the name of Quake had a couple more years to establish itself.

I lost hope in GOG when they kowtowed to political pressure groups and delisted Spec Ops: The Line.