IMO I'd stop thinking about breeding mice and start thinking about breedng rats or ASFs. Rats dont smell as bad as mice, and ASFs dont smell as bad as rats. Also rats get up to size faster than mice, plus if you think about the future you're going to need a heck of a lot of mice(4-7 full sized mice per snake) to feed adult sized ball pythons whereas if it were rats you'd only need one medium rat per snake.

Just my