I recently in the last week let my whole collevtion go to a close friend of mine. But i still help feed them and everything and see them almost everyday. The collection total is 21 adult 12mths+ , 9chams 4mths-12mths, and lots of babies. WE only go through about 3,000 crickets a month at the moment because we are breeding silkworms, hornworms, dubia, supers, grasshoppers, and mantis for the collection. Usually we have four feeders that we can consistently feed every month for variety depending on hatch times of bugs and such. with 20-25 chameleons and a diet of mainly crickets you will need around 6,000, maybe more. Crickets die easily and in great numbers if not maintained well and escape cages very easily or just get out in the cages and hide til they die. Lets just say you'll need a whole lot of crickets and a whole lot of time. At least with that many cricket though you'll never have to buy fruit flies for hatchlings because you can always have pinheads on hand.
Justin