Ok, just my two cents.. LOL, ive only had my salazar for about 2 weeks but ive done lotsa research and heres basically what you need.
You can start with something small like a 10 gallon for a hatchling, thats what i have. CHeep $10 heating pad stuck under one half of the tank.. hide box on the cold and hot side, water on the cold side, and substrate. Reptile carpet, aspen shavings, etc.. is good substrate. They like to burrow, so the aspen is good.
Eventually yes you will need at least a 20 gallon long. I have been pricing them, while the tank itself can be found cheep at yardsales and such, ive been pricing themand they have really nice reptile tanks with built in locking screen tops for about $60 for a 20 gallon. Not bad really considering the lids can sometimes be expensive if you want the locking kind.
Mice, yes you have to feed mice, but they aren't really that expensive, whats $1/week? Pinkies around here are about 60-70 cents apiece and i just bought 15 frozen pinkies from my Pet store for about 8 bucks. Of course, i had to have them ordered, if you cant find frozen, talk to the managers of local pet stores and ask them to order frozen for you, most likely they will.
and thats about it.. hope i helped a little bit.
btw.. i hate how everyone always tells you to search, it would take just as much time to type some advice in as it does "do a search".. forums are so you don't have to search.. lol. This is the only forum ive ever been in where people don't answer the question, and just tell you to search.