Modularize and Reuse asp.net C# application

[Scottie]

I want to implement a shopping cart website in asp.net C#. The UI and logic implementation is pretty complex.I want to be able to use this shopping cart application under different ASP.NET websites.We have 12-15 different websites in asp.net. Each website is a different business model. However, we want the same shopping cart application (with the same UI and logic) to be under each of these websites.The concept sounds like a ASP.NET Server control i.e create the shopping cart as a ASP.NET server control and plug it in different websites. However, the following are some of the issues we are facing:-[*]The shopping cart UI/logic is pretty complex. Easily can run into 50-60 aspx pages. I am not sure how easy and maintainable will it be to create this as a server control[*]How much performance impact will we have to face as compared to a standalone shopping cart?Performance impact is more important for us.Finally, is there any other better alternative to handle this plug-play design in asp.net for complex projects.