7,500 yen? That's $75.41 in US dollars. That's the cheapest I've ever seen for one. Most others are well over $100 even the shitty ones. Wish I could have gotten one...
You are obviously looking at the wrong places. $75 for a loose Famicom isn't exactly the deal of a lifetime, nowhere in the world. Also that lot is just a joke I suppose. NOBODY would pay $75,000 for a bunch of yellowed loose Famicoms.