It is the same with registered purebred kittens. A kitten from a registered breeder comes with a pedigree that proves it is the breed they say it is. Unregistered breeders just breed cats that look like the real thing. The only difference between kittens and designers bags (aside from the fur!) is that kittens from registered breeders dont cost more. In some cases they cost less especially when they have vaccinations, microchipping and desexing included in the price. Registered breeders follow the standards set by their asociations and breed for love not money.
So buyer beware. Dont make the mistake of buying your kitten from an unregistered breeder. Why have a cheap knock off when you can have the real thing?