I am not too sure why you would want to willing feed a venomous animal to any other animal?

Livefood is not expensive. You can buy a tub of crickets for £2. If you can't afford that, then you can't afford to look after any pet, let alone a reptile. What happens if you lizard becomes ill, can you afford to take it to the vet?

Capturing animals for you lizard to eat is dangerous. You don't know what the little beasties have been sprayed in or lived in etc etc.
I heard of someone feeding a spider to a Bearded Dragon once. The Beardie passed away sadly.