I am glad you like WF and the demo and thanks for the feedback. Please note that the sample is for demonstration purposes only to show you how you can leverage WF rules to drive the business logic of a windows form application. WF recommends that you model your application to fit your business needs and if hardcoding the items' prices doesn't meet your needs then you can pursue other options. One option is to create or reuse an internal structure and the rules can lookup values from this structure and manipulate the UI controls accordingly. Hope this helps.