IMO, forget crickets. They are too much hassle to breed. If you
are successful getting them to breed (and most likely, you
will succeed) you are going to end up with a LOT of crickets. 2 leos will not be able to handle all the crickets you get.
Now getting lots of crickets might sound fine but they do need space and food and care. A few crix in a tub are no problem but when you've got them in the hundreds (or thousands) and you have nowhere to put them you have a problem. In the summer it might be fine to let the extras go outside but come winter, you will be stuck.
If you can find a few friends who you wouldn't mind giving crix to it might be okay.
Anyway, a much better choice is to breed mealworms. Doing it is incredibly easy and requires very little upkeep.
So in short, this is an easy way to breed crickets.
First, I'm assuming you know how to care for adult crickets so I won't get into feeding or heating or any of that.
Take a half dozen to dozen adult crix and put them in a container with a bowl of moist soil. After a week, the bowl will be full of eggs. Remove the bowl and put it into another container to raise the babies. They should appear after about a week or so. You will get about 500 babies here. Repeat the process every week with a different container and you will have a constant selection of crickets in various sizes. The keys are moist soil and heat.
You might be thinking you can get away with just raising one batch of 500 crix but it takes a while for them to develop to food size and by the time they are ready for feeding you only have a small amount of time before they grow up and die. You will definitely end up with more dead cirx than food crix
But give it a try. There is nothing to lose (but your sanity).