Check into the permit system. You need permits to own which was no big deal, I think it was $10 or $15 a year when I lived there but if you had a certain number of animals they considered you a business and you needed a $150 permit. You also need permits to simply posses animals. So any out of state breeder would need to provide the state with a list of all animals they will posses and pay whatever fee was required. You would also need to plan months ahead of time since the state takes time to review and return a permit. It's just easier to vend in NY and PA. Plus, NJ was known for tight enforcement which probably scared people away. I'm a few years removed from NJ so some things may have changed but the system is probably the same or similar.