asp e-commerce enhancement

This is an upgrade to an existing custom e-commerce system which sells varying types of subscriptions to the website via worldpay. The upgrade will be to construct a simple page offering other digital products and bundles of existing services. However integrating the new functionality into existing code is likely to require revisions of ASP/Classes/Stored Procedures since system designed to sell one service at a time. Proven ASP / MSSQL experience needed. Estimate is 30 hours work.