Depending on the content you have on all those pages, you might be able to use the Custom Capabilities for each Item/Level combo, and use a single page and protect the content with conditionals. So you could have everyone return to the same page and have the links or content visible only to those with the proper ccaps.
Another option is with the s2Member Pro, where you can assign a success variable:
success=”” Success Return URL (optional). s2Member handles this automatically for you. However, if you would prefer to take control over the landing page after checkout (i.e. your own custom Thank-You Page), you can. If supplied, this must be a full URL, starting with http://. Your Success Return URL is only applied to (new) Customers.
Hope it helps.