I have made my searchs on eBay for your information. However none of these deals appeared in my area.
I can't even buy that Duke nukem, and the auction will end in 6 days. Thus I'd have to wait for it to maybe get it for cheap.
Also note that I mentioned ultima VI (6), not ultima VII (7).
In any case, my initial point was that getting original games is expensive.
Maybe not super expensive if you go towards cheap rereleases that nobody wants, but then getting them from gog is even cheaper and easier than having to get them used (at least when they're available, some are missing I give you that). The fact you can buy them from gog (or just pirate them) is probably another reason why nobody wants them.
The same Ultima 7 collection you listed is available here for 5 bucks https://www.gog.com/game/ultima_7_complete
Even if the guy can't sell it for 55, you'll never get it for 5 from him.
Ultimate doom can be gotten for 5 bucks
https://www.gog.com/game/the_ultimate_doom
By comparison it's like saying "you can also go for cheap computer parts instead of going for the holy grail like the 9800xt and still have a good retro experience. Just pick a cheap pentium 4 box stick a mid range video card and you can run what you'd like for the time period you aim."
Which would be true, but maybe not what you want or expect.
This was I initially meant :
wanting a modern cheap and readily available hardware solution, then wanting the original game releases that aren't so cheap and longer to get in comparison to online re-releases because that's the "retro experience" sounds contradictory to me.
As usual, what's retro and what's not is a matter of opinion ... To me, playing on an emulator is a valid way. Playing on original hardware is also a valid way. Using original or copies gotten from the internet is valid as well.
I personally prefer to stay with original hardware and original copies to avoid quirks (bad emulation, bad dump or an issue with a re-release) but it didn't prevent me from finishing some games on emulators even if I have many retro PCs at hand.
As for newly made hardware, I think it'd sell better among the masses if you made a contract with GOG to ship it with some classic games and have a hardware support as broad as possible (especially with sound in DOS, speed accuracy comes second). Of course adding more games from either originals or online should be possible.
By the way how is that gonna work ? Do you plan to put a floppy disk connector and an ide connector ? Do like the pi and rely on an SD card and use usb devices ?