Very cool! Lucky you, I can't find it in my area I am going to have to resort to ordering some. I was given a bit from a friend out west, but I need more until mine grows more!
Next time you go to the store ask to talk to the produce manager, then ask him if he would order you a package of cactus (Nopales). He might have a minimum order. When I asked my produce manager to order dandelion greens, he ordered one case. I bought several bunches and he put the rest of them out for his other customers. He actually sold them. Your guy might be surprised too, that others might want cactus.