I know it sounds like a lot of crickets, but they really do need them. Not every dragon will eat 100 per day. It depends on the dragon, the size of the crickets and etc. Our BD is still a baby (just over 7" now) and easily is eating around 30 3/8" crickets per day.
But, crickets can be bought on-line a LOT cheaper than in the pet stores. Even with overnight shipping, it's literally 1/2 the price the pet store charges. You can easily keep them in a plastic storage bin - as long as they have a wet sponge for water and some food (a huge thing of Flukers cricket feet is about $6) they will be fine.
Yes, the initial expense is up there, but maintenance expenses once they get older aren't any differnt than other pets.
And, as they get older, they won't require as much live food, so the feed expese will decrease. Greens/salad stuff is cheaper than insects. Heck, you can grow your own during the summer
You can even grow your own insects at an extremely minimal cost if you have the time/ambition.
A bunch of mustard greens cost around $2.00. plus some of whatever other vetetable/fruit that is in the house - that's $20 or so plus some insects. Really not much different than feeding a dog. I spend about $50 per month on dog food - and feeding our lizard will likely run about the same.
Please, find a way to feed your BD correctly, or at least find someone who can if you can't. I know not everyone can afford a pet, and sometimes something like a lizard seems like an inexpensive pet. My anoles didn't require 1/2 the crickets these guys eat at the same size.
If you didn't know- you didn't know - not necessarily anyones fault. They don't always tell you that kind of stuff at the pet store. I know they didn't tell me, but i had done some reading beforehand so was expecting the large quantity of crickets.
They just sell the animal and let you figure out the rest and don't tell you what to expect for feeding/maintenance costs.
It's sad, really. Pet stores should be required to post expected care requirements by the animal so people can at least be somewhat informed before impulse purchases. (I know a lot of that info is not always correct, but at least it would be a start).
I hope you can find a way to care for your BD...