About how much a week would it cost to feed a Bearded Dragon and a Plated Lizard?

I have a bearded dragon and would love to get a plated lizard to add to my love for reptiles and i was just wondering since i feed my beardie super worms and they are about 4 dollars for 70 a week i feed him 10 a day. About how much do You think it will cost me a week to feed a bearded dragon and a plated lizard? i am able to mow my mothers lawn for about twenty bucks will ten be enough for two weeks? just wanting to know if it will cost a great deal of money or not. thank you! oh, and do you think it is a good idea to get a plated lizard should i get rid of my beardie before or keep it and forget about the plated lizard, it all depends on which is easier to tame.