I think the point needs made, and Wolfy touched on it in her post, that breeding your own feeders is not always just about saving money on your feeding costs.

I started breeding rats when we had about 5 snakes. Partly due to the cost savings (the pet store was awfully expensive) but also for two other even more valid reasons.

#1 - the pet store did not always have in stock the exact sizes that our snakes needed that week

#2 - though they did breed their own rodents and the quality of care was very high, that's not always the case in most pet stores that simply bring in feeders in bulk and often overcrowd them

Whether you want to have rats as pets, as pets that breed feeders for you, or straight up breeders for feeders that's your decision. The only thing I'll suggest is you simply purchase the rats from a source that knows your intentions. To lie to a pet/show rat breeder only gives other snakekeepers that breed rats a poor image so I'd avoid that.

You may well be able to find a member here that lives near you and can sell you a couple of lovely just weaned females (try starting a seperate thread on that and see if you get any responses). If not, you can check into reptile shows in your area, often rat breeders attend those. Last would be to check into local pet stores. There's nothing wrong with pet store rats from decent pet stores that care for them well and keep the males and females seperated.

Wherever you buy from, purchase recently weaned rats of around 5 or 6 weeks of age. Check them much as you would a puppy or kitten - clean bright eyes, dry nose (no red discharge from eyes or nose), clean dry butt, no sores on tail or the bottom of their feet, a nice clean coat free of bugs and laying flat to the rat's body (not fluffed up or mangy looking), no scabs on the skin under their coat, good body weight being not fat or skinny. A decent temperment, the rat will be skittish but shoudn't be obviously aggressive to you. Color and pattern are your choice but if you do intend to breed you may want to do some further research on certain genetic issues that you see more often with certain colors/patterns of rats.