On drink pricing you should visit your local competition, you have to be in the same ballpark as them, if your product is better you can be higher and get away with it. Use the big green as a good price average. Your food costs should run max 33%, preferably less.
Pricing strategy is a fairly complex matter, the best book that I've read on the subject is The Strategy and Tactics of Pricing by Thomas Nagle. If you are looking to develop a unique strategy for your own company, I highly recommend it.