I assume that you can’t have raw meat on your dog cart, so you would be buying sliced, pre cooked roast beef? Then hold it in aujus? Then add pre cooked peppers & onions?…….Stick to the dogs, that’s what I would be going to a hot dog cart for, not a bastardized cheese steak.
As far as cost, what does it cost you to make? What would your market bare?