Looks like I missed the drama of this thread..l but I thought I'd lend my view:
I have bought large orders from rodent pro and sold extras to local reptile owners at a dollar a mouse.
I have bought live, killed them (CO2 is easiest, IMO) then frozen them.
Risks of fresh killed are parasites, but also I think they tend to smell worse before being frozen (I left a fk rat in with a python for a few hours and holy crap, the smell was terrible! Usually I would offer it to someone else but I just tossed it. )
Also if a snake is used to f/t (that is wet and hot) they may not like fk that is dry and cooling down.
Keep in mind that freezing does not kill crypto (which is transferred through snake feces, so a mouse breeder who has snakes and mice and has poor husbandry could get snake feces on the mice, thereby giving your snake crypto).
This underlines the importance of knowing the quality of husbandry from where you get your mice.
As for starting a mouse colony: I've had terrible results.
My male was biting my females to the point that one female had fairly bad wounds and I had to separate her. She got lonely... So I separated the male and rotated the females through. Pain in the rear.
My white female got pregnant, ate all her babies. She got pregnant once more and I managed to save most of the babies before she got to them. Third time no such luck.
The injured female never got pregnant.
The other female got pregnant once and I took the babies before the other female could eat them.
Result: I spent $6 in food, $4 on a water bottle and $6 on mice. I got 17 pinkies and a pain in my rear. I spend $0.18/ pinkie online (plus shipping, obviously)
Other negatives: you have to check/feed/clean every day! Missing one or two days can result in near death or death.
They smell. One mouse smells worse than 150 snakes.
They bite. Snake bites? Give me a break. Mouse bites hurt and bleed.
I may try again just because I hate to be defeated, but not to save money or because I'm worried about quality- I trust RodentPro.
Also- reptile expos usually have a frozen mice vendor there where you can get pretty cheap mice.
I would totally recommend rodent pro, though- and get something like 50 of the current size, 50 of the next size up and so on and fill the box the rest of the way with adults. If you run out of smaller sizes, you can always supplement with local options- and you will eventually need the adults.
Plus, you can sell some if you need to.