Crickets can be raised, but there are several considerations. Smell, escapees all over the house, chirping, and die off in the pinhead to 3 week period.
Many start down this path and realize that at 2-3 cents a cricket when you buy 1,000 from a real cricket farm, it isn't worth the time to farm your own. If you want the challenge of doing it yourself, google "raising crickets."
How many crickets do you need in a month? i don't use crickets often, but when I do, I buy 1,000 in a smaller size than i need, and go through them in about 3-4 weeks. LLLReptile.com has low prices, Ghanns is known for the best quality, and there are dozens of others out there.
Presently there is a cricket virus in many of the cricket farms, and they die at about 3-4 weeks old (they die quivering on their backs), so if you are getting breeding stock, be sure to ask if they are virus free.
Hope this helps
Nick Barta