There is 3 ways this works.

Breed based, they go off some questionable basis and people pay more for those.

Training based, they go off real information and we get better trained dogs. Line info also helps. So a well trained animal from a line well behaved animals is cheaper. This is good for all of us.

Breed blind, responsible dog owners pay for irresponsible ones.

I would go with training maybe a mix, if you have a questionable breed you can send it off to a qualified trainer (with insurance and licensing) for intensive training to pay less. Making things breed blind does not encourage people to get real dog training thats required to make good dogs. I'll trust a pitbull thats passed through a few months of in kennel schutzhund training over somebody's little fluffykins purse dog any day. Split the difference and if it can pass the testing even.