I use a spreadsheet from restaurantowner.com. It is one of the benefits from that subscriber based website. I have seen other spreadsheets that are free, but I get a lot of management tools from restaurant owner I can't find anywhere else.
My selling price is determined by estimated expenses. I must have enough net profit to cover expenses with what I am happy with left over, and balance that against comps. I use the spreadsheet that breaks everything down by an inventory list. Inventory items are broken down to ounce, or volume, then a recipe (batch) is built from the inventory list for a menu item whether it is a bulk sell or individual. So to summarize, I start with expenses then I work backwards to determine my sell price.
Here is a batch example for a burger:
Bun 1ea $.10
American Chz 1ea $.10
Ketchup oz fl .25 $.01
Must oz fl $.01
CAB Patty 1 ea $.95
Tomato 5x6 oz .5 $.04
Lettuce Rom $.03
Batch Cost 1.24
Hope this helps and is clear.