I don't think 2.50 is too high, but if the piece was that small just make them bigger. First figure your excact costs to make a pie, then at least triple that (just a guess). Then are you looking to make anything, how much, or just for a hobby. Do it for a few weeks, month or so and keep track, then is it worth paying what he needs for utility use and are you making anything. I would go for at least 6 toppings. Pepperoni, olives, mushrooms, onions, green peppers and at least 1 second meat, sausage or ham. All are very stable in the fridge, the sausage would be the least and then your cheese but I don't really include that as a topping, most expect that. The sausage you could pre-cook and keep frozen although that lessens the quality a bit. Onions and green peppers can be cut to order unless you get swamped then cut a bit more. Also does he have a food license and inspected/approved kitchen, insurance, refrigeration etc. Many things to consider before you jump.