I find that my rats and mice take way more time than my snakes. But I do enjoy breeding them and I'm sure my snakes will love the abundant supply of live food once I'm up and running. Just had a few new baby rats and mice for the first time, still buying 6 mice per week from the local pet store for $1.75 each until my production is up. I could probably go through 20+ feeders per week with my 15 snakes if I switched everyone from frozen thawed to live.
Back to the original question, I think you could breed mice or rats with just one snake. You could put the male and female together until they have babies, then separate to control the breeding. Once you get low on babies put them back together. As long as the babies don't get too big to feed, of course you could always freeze the extra or switch to African soft furs or mice that will never get too big for a ball python.
I've often thought that it would be nice to have someone else locally raise up mice and rats for me, as long as they were willing to sell them really cheap, like 50 cents a mouse or something like that, maybe a dollar for a rat... Would save me a lot of work. I'd almost be willing to set them up with a real nice rack system as part of the deal. Maybe I can go door to door down the neighborhood and ask around LOLOL.
By the way, some people think that breeding mice and rats is too expensive. It basically comes down to the price of food and bedding. If you could get both for free then the mice / rats would be free (not including labor of course). The feed store has really cheap feed, some is less than $10 per 50 pounds. If you had the right connections you may be able to get expired feed from the supermarket and bedding from a sawmill (or something similar for free).