starting mouse colony

We are going to be starting a mice colony for feeder (f/t) mice. We are interested in black, brown and gray mice. Does anyone know where we can get the "parent" mice to get the colony started? Now that we are up to 70 snakes and have 6 pairs who we hope will breed, though they are being stubborn right now, buying mice will soon be expensive. I get my mice from American Rodent and the prices are pretty good. But even so, $300 in frozen mice in the freezer with $300 on the way still won't last through the year. So we are hoping to get our own colony started this spring. I also have friends who need mice too so this will be a win/win situation..hopefully..plus I want to keep 2 for pets. We want to get the racks started first but still need to find out where to start

I bought my fancy mice from the petshop here, I also got a breeding trio with babies off kijiji.
I know there are a lot of breeders in USA who breed for pets or shows, but they think snake owners are evil lol!

I always start at any given pet store whenever I get a colony going again. They're generally healthy enough and you can usually pick them out. The first babies can be tough though, I usually plan on the second generation to be the actual colony.

I have heard pet stores don't sell both sexes. Can't remember which one they do

Petsmarts sell one sex only, mine only sells males, I wish they had females I would buy a bunch! It's hard to find females here, so 95% of the mice my snakes eat are males. I do gas my older females when they stop producing. I sex the pinkies/fuzzys/hoppers and cull the males first.

Petsmarts here sell both sexes, but I usually dont go there cause they're annoying about picking them out, often only have white, and I think that's where they had me sign something saying they weren't for food. I like small pet shops for that.

Yeah I bought 5 anoles off them to scent a pinky for my fussy eater and had to tell her 2x that the anoles will be kept as pets, they will get the odd dead mouse rubbed on it lol!
The anole scented rat pup was a huge success! Never seen that snake eat so fast!

Mice are old when they reach 1 year of age. For good reproduction you must use mice younger than 1 year. Your pet mice most likely will not thrive for you much past 1 year.

I bought live feeder lab mice from the petstore to start a colony. they were all dead within a month! I can only assume that the supplier didn't take great care of them since they were going to be used for food. I treated them the same as my pet rats so I know it wasn't from the way they were taken care of by me.
I ended up looking on local on-line classifieds and got a breeding colony from a well establised colony.
Best of luck! I believe that some petsmarts are single sexes, while some sell both sexes.