OotG and Darkwing Duck aren't rare, there are just as many of each as Magical Chase, which also isn't rare. The "rarest" Turbo game is Dynastic Hero, which was supposed to have been mail order only. As long there's been a trading or selling market for Turbo games online, I've seen Magical Chase available regularly, unlike many other games that don't have crazy collector prices.
CD games aside, there is evidence to suggest that MC is the rarest Turbochip. I've posted some arguments in the past here and here.
There's a tendency among greybeards to cross their arms and sagely inform newcomers that "pfff...Magical Chase isn't rare!" Yes, we see it traded a lot, but that's because the rarest Turbochip will always have the highest demand, not because it's common. There will always be an endless line of impulsive, desperate guys like alexsduo willing to do anything for a copy and after six months they'll be the next royvegas trying to get out of debt, buy a house, or get married and we'll see the same copies for sale again.
Although MC has always had a reputation of being uncommon, up until the recent market manipulation, it always sold at the most, for equal to or less than other Turbo games like Beyond Shadowgate.
How far are you going back? I'd say that the market really went to seed in 2007. Before that, young collectors were fairly rare and BIN hadn't taken over ebay. MC has consistently been the most expensive U.S. game since I started paying attention at the beginning of '05 and copies of BS have never been close. Even in the Nineties, it was exceedingly rare: TZD sold out instantly and Radioshack and Games to Go (MPLS former Turbo Mecca) had Dynastic Hero, Hero Tonma, OotG, and Beyond Shadowgate, but not MC. The only time it ever seems to have been merely uncommon was when there were a handful of collectors on the Turbolist and they were more interested in SCD RPGs than yet another Turbochip shooter.
From the late ninties onward. Even on this forum for years people scoffed at the ridiculous asking prices as high as $100. Not simply because no game is worth that, but because, like many games, you could get it at a decent price if you simply patient. But it was one of those titles that non-Turbo-fan Turbo collectors happened to have trouble finding instantly when assembling instant collections and it gained a reputation within the non-Turbo-fan collecting community, which ran separate from the reputation with the Turbo community. All it takes is a ridiculously incorrect rarity score in a bullshit rarity guide to destroy a game like this. Anyone who has to reference a guide doesn't have a feel for the subject and is basing the value of something solely on what someone or something tells them.
Independant and U.S. Only releases like Klax, Sidearms, Tricky Kick, Parasol Stars, etc probably have very low print numbers by TG-16 standards. Some may actually not be as low as Magical Chase, but if they're still some of the lowest, then they should go for hundreds of dollars if rarity is the driving force of MC prices.
I'm not saying that MC isn't rare by general video game standards, all Turbo games are. But there's no way MC is much rarer than several other Turbo games that don't go for crazy prices. Ever since I got online I've always seen MC for sale or trade, but for years I never saw games like Darkwing Duck, Legend of Hero Tonma, Beyond Shadowgate, etc.
For the MC prices to reflect its rarity, there shouldn't be such a huge jump in price between it and other Turbo games. Dynastic Hero is definitely much rarer, but even its crazy gouged prices are maybe half of MC's and Dynastic Hero has always been harder to find. Especially back in the day.
Even if it could be proven that MC holds the title as having the lowest print run, the number is still not that low. No Turbo game is. There seem to be way more MCs than System 3.0 cards, but even those aren't that overpriced.
There is still no logical explanation based on supply and demand, that MC should remain steady at $100 - $150 tops for a long time and then jump to $500 and then the sky's the limit. Did 90% of them suddenly disappear?