There's also a french car collercor who had ordered the entire lot to be destroyed upon his death, I cannot find it now though.
I remember (I think) during the Cult days there was someone bragging about a proto but never dumped it so he was mocked to the point of taking his ball and going home. I think. Maybe I'm making it up. I'm getting old.
Mind-blowing that after nearly 20 years it just happens to show up on a random £30 ebay lot. I do wonder about the timing though, why now, anyway? Sonic 1 prototype cartridges are not exactly something that gets forgotten and sold for scraps very frequently. I can't help but wonder whether a pandemic that hits seniors the most helped expedit things, but maybe I'm getting too grim. Anyway, don't be mad that Buckaroo made a killing profit out of sheer dumb luck. The more important angle of this whole story is that everyone got the best possible outcome AND it sets an important precedent for future collectors, namely that you might want to get your stuff dumped and verified by a reputable source like hiddenpalace.org if you want to get a good price for it. Because let's be honest, not many people would have taken a cartridge like that, randomly showing up on eBay, seriously, even if it claimed to be a prototype. This idea that undumped cartridges are more valuable may well be outdated in an age where fake youtube prototype footage fools even Yuji Naka himself.
Are you saying the disk was never found again, or it was never dumped? Because it was definitely dumped: https://hiddenpalace.org/Super_Mario_64_(Nintendo_64DD)_(Prototype) Other examples of undumped games that private collectors have are Marble Man (the Marble Madness sequel) and the Arcade version of Beavis & Butthead.
wait, how I could forget? The SegaSonic Bros arcade game that we basically only had screens of forever because the collector was leery about publicly dumping it.
The collector is still being that much of an arsehole, he said that he wouldn't sell any more machines if the ROM were published. The wormhole was that the people who bought and dumped the machine altered the ROM, so as it's not a 1:1 copy they could publish that. If you ask me, I cannot find any reasoning for that thinking... what do you win, as collector, on doing so? If you already sold the machine, your income or anything will be altered in any possible way if the roms get published. That's just being an arse to me.
Between this community and Pokémon's, I've been having field days the last few years. Videogame development investigation is something I enjoy reading and watching about. Check stuff that got left in the cutting room floor or recycled later on is always intriguing.