Morganshow11, you can't even afford one rat! Why the h*ll do you think you can afford to breed!? That's at LEAST three cages (aren't you still saving for one cage), food and bedding for a possible 20 rats, plus the possible medical bills if something goes wrong. Plus, pet store rats SHOULD NOT BE BRED. They are nott well bred and have many issues with tumors, and are more prone to general illness then a well bred rat. They have shorter life spans too.
And what wil you do with the babies? It's not easy to find homes, why do you think rat rescues are over flowing. There is a good chance your only option would be to sell them for snaik food. ""There's nothing wrong with that,but are you willing to do that?