I really think with an investment of a few thousand dollars a person could make their money back in a year or two and here is how:
buy several normal females, breeding size can go for $100-$150
buy several low end dom/co-dom males, spider, pastel, ...
buy an albino male and 3-5 het females
you could be producing pastels, spiders, and any other dom male you have the first year, and maybe albinos and bees the second year. Could probably buy all of those snakes for under $2K, another $1K for racks, incubator, other equipment rats and anything else you need.
This wont make you rich, but with a small investment and growing slow and steady every year, I dont see why a person couldnt do this.