i have been doing my feeder math as well and i am actually picking up a breeding trio tomorrow. heres some things i had to get

a 20 g tank for the male to live in
2 10 gal maturnity tanks
2 68 qt tubs to house weaned rats (male/female), with hardwear cloth to make tops.
5 water bottles
5 food dishes
a nice large bag of substrate
food: rolled oats, rasian bran, puffed wheat, senior dog food, and fruity trail mix

as of now i need 8 pinkies, 1 pup and a small each week. to me it's worth it, as i plan on only breeding 2 females, so i won't have too many numbers.

i easily spent $60 not including the rats, on this set up, (i had the tanks laying around too so you might ave to buy all those). it's alot more work then it sounds.