I'm pretty sure I'm not incorrect. Lets look outside NEC, take Nintendo for instance, they have games that were massively produced and cost buku bux because no one wants to let them go, then on the other hand you have games that are really rare and cost next to nothing, Nintendo has a game out right now and as crappy as it is, it's A+ rare and cost 2 dollars because people do not know it's rare "Nintendogs" or some crap like that. So rarity is in the eye of the beholder i guess. As for me I could care less about rare, cost, etc... I collect, I play, I love my systems and when I do have the chance to get "rare" games I don't pass it up.
If you ask me MC is not as rare as some of the other games out there for the system, or other systems, it's the simple fact that people hoard and create a false rarity. Nintendo is doing that very thing right now with these stupid amiibos, producing "limited runs" of certain models, does that mean they are rare?? nope not at all, does it mean people will charge stupid prices for them?, more than likely. Bottom line the word "rare" or "Limited run" really means nothing anymore other than a price tag to some people. There is nothing that can't be had for a good price with patience and time.
If MC is so rare then why when one goes up on the market they are followed by a bunch more? It's people looking for a price point they think they can get, and when they see one go for tons of money they think it's time to cash in. So all in all, its a created state and a load of BS if you ask me, but thats just my 2 cents.