I had a neighbor in California trying to sell a nice, very large vase at his garage sale. It looked antique, but he wasn't sure what the value was, so he priced it at $15. This is before the internet, where you could look up things on Ebay etc and get an idea of value.
Anyway, no one wanted it. So he had another garage sale a while later and priced the vase at $500. People were arguing over it and it sold.
Maybe these wildly priced quilts are supposed to trigger people to think it really is a collectible item. Most people are completely clueless about even the cost of good fabric, let alone what it takes to make a quilt that will last.
People ask me to make them one, but turn very pale when I tell them what my time and efforts are worth, whether they provide the fabric or not. They can't comprehend my work being so much more than the ones they could order for $69 from QVC!!!
My grandmother used to knit gorgeous afghans for family. Her neighbor offered to buy the yarn and couldn't understand why Gramma said no thanks. That was at least 500 HOURS of her time to knit it, and who wants to do that for free?
Bottom line: Make quilts for yourself and friends or family because you enjoy it. If someone wants to pay you to make one, don't cheat yourself. Charge for your hours, the supplies, everything!