Saul,
There are many facets to what you are trying to do. I think the following article by Big Dave Ostrander, a former independent pizza operator and now a consultant to the pizza industry, may be useful to you in this regard:
http://www.pmq.com/cgi-bin/tt/index.cgi/noframes/read/20402In the above piece, there is reference to a portioning chart (Burke chart). Instead of signing up for a download through the Pizza Marketplace link provided in the Ostrander article, I found it at another location, at
http://www.pizzamarketplace.com/RightToppings.pdf. The key pages of that document are pages 22 and 23. Please note that there is an error on page 23. The amounts specified for pepperoni should be in pieces, not ounces.
At the bottom of the Ostrander piece, there is a link to a software product called Food Cost Pro. It is a product sold by Ostrander to pizza operators. If you click on the link, you will see how it is used and what it can do. If you subscribe to what Ostrander is advocating, you would want something like the Food Cost Pro software. You could use Excel spreadsheets, but as Ostrander points out, they are prone to crashing.
Until you go through all the steps of identifying pizza sizes, the possible combinations and amounts of toppings, and what it costs to make each pizza, you really aren’t ready to talk about the prices to charge. Of course, as chiguy has mentioned there are many other costs of doing business that also have to be taken into account, but resolving pizza costs is central to whatever you plan to do.
Peter