Why not do like another member here. She finds a mouse breeder and buys as many as she needs for a month or 2, and sets them up in her quarters and feeds and waters them. She buys bulk, so it's cheap (think reptile show or private breeder, get in touch with me later) and if they breed, good stuff, if not, then it doesnt matter.

I know you think it's cheaper to raise... but is it really? Taking into account all the hassle of first getting mice to breed (notorious for cannibalism) and the amount of feed, housing... It does get pricey.

I don't want to discourage you, just trying to give you ideas. I can't imagine waiting 8 weeks for a litter is much fun, but if the litters are consistent and enough to keep 2 snakes fed for 8 weeks, then yes, in theory it should work. Just don't put 100% reliability on mice. (from others experience)