Calculate Recipe Cost for menu changes

By sunday, I need an asp.net c#, ajax application that allows my customer to calculate the cost of their menu items when feed a large group of people. Think of an web application that has a SQL 2005 backend. The user logins and sees a menu list for each day. The user see a menu with their Breakfast (morning meal), Lunch, and Dinner menu. The concept here is that we are going to list the items and their cost factors and the quantity used to calculate the cost per meal. so if Breakfast let say that Breakfast has the following menu that will feed 100 people. 1/2 case of cream of wheat, 1 case of Eggs, 2 cases of jelly personal size, 1/2 of margine cups, 1 case of diet jelly. With having the inventory in the database and the price in the database. We give the user the cost of the meal for a 100 persons. We allow the user to make changes to the menu and allow them to dynamicly see the cost change for the meals. Now we have think of the user having menu plans for everyday for a month times three meals a day and a snank menu during the day also. Ok, I really need this by sunday, so if you are like me and already have too much work to do then do not bid ok.