As I said in the other post, Bananas are actually very high in sugar- making them not that great of a feeder. The crickets will go nuts for them, but the cham will get very little benefit.
Romaine, endives, carrots, apple, oranges, honey, kale, sprouts - all good and cheap items that can be used to feed the feeders. Keep in mind you do not have to give them first pick of the food!
when your cleaning your carrots, give the shavings to the crix. The dark parts of the romaine? to the crix. Apple core? to the crix. left over salad ( no dressing )? to the crix.
When you do it that way, the cost becomes very little... in fact its almost recycling.