Well I can tell you as one that wants to breed both professionally, you will get greef from both sides. Especially from the rat community. Rat people are very particular about who they sell to. If you buy a rat with great genetics and breed it to another rat they will be offended. Also most people with the rats that are you looking for will not sell them as breeders but as pets only. Aside from craigslist most professional breeders will not sell to you. From doing research, if you want a breeder from a professional breeder you need to develope a relationship with them for a couple of years before you can get one, then your looking at a price tag of about $75 plus. It would be a waste of money to pay that much just to feed the babies off, or even a portion of them. Your best bet is to breed pet store rats for feeders. If you want to breed rats for pets you need to keep them in a seprate area away from them, to keep diseases undercontrol.