the shelter i worked for just banned breeders recently because we had s/n requirements like that and people kept arguing with us over it. we had someone who bred and sold bengal kittens and did not want any vaccines because they insisted the rabies vax killed their original queen. we told them it was the law in PA, got all 13 of the kitten vaxxed and checked, it was like $1000 for 13 kittens to get vaccines and wellness appointments. that's $76 per kitten, super cheap.
well they complained about the price. a week or so later, the kittens came in for s/n and they gave us a paper with their markings, sex and which color collar they had. NEXT TO EACH COLOR THERE WAS BLACKENED SHARPIE MARKS, SO I HELD IT UP TO THE LIGHT AND THEY WERE SELLING THESE KITTENS FOR $3,000 EACH, WITH THE EXCEPTION OF 1 THAT HAD "UNIQUE" MARKINGS FOR $4500 AND A MALE THAT WAS CRYPTORCHID FOR $2,000 INSTEAD.
thats almost 40k...that is literal college tuition....