Simple PHP interface to an order & item database (specifically, MySQL). Involves: list of possible items as part of the order, individual order listing (incl. item ID, name, quantity, initial funds, order date).
Automatically updates prices, etc. with JavaScript (as well as maintaining a running difference from initial funds).
Designed to manage order history & "ingredients" of floral arrangements (hence "recipe"-manager), but should be adaptable for similar purposes.
These details are provided for information only. No information here is legal advice and should not be used as such.