Tyrian 2000 is absolute bullshit hard to find, I'm looking for that one too, and original Tyrian was only released in a big box overseas.
You know what's funny is that I actually saw a US big box Tyrian 2000 in a lot with a bunch of other heavy hitter (e.g. usually expensive) big box PC games that sold for $4k a couple days ago on eBay, 90% sure it was someone liquidating their collection through a private deal because it sold pretty much immediately, and I don't see it in sold listings. I don't think I've ever even seen a disc for Tyrian 2000 within the two years that I've been looking for it. I practically pissed myself until I saw the price.