Basically, the ignorant people who breed them have created a demand for designer mutts by breeding a cute, shaggy dog, and BS'ing it as better than purebred. I think the reason why they can get away with charging $500 to upwards of a Grand, is that most papered purebreds sell for around and upwards of $1000. So, the breeder tells you that their dog is cuter, healthier, and sheds less than a purebred, and they charge 80% of the price of the purebred. A poorly educated customer would be convinced they are getting a deal.