Goldbar one is an all in one payment system, autoresponder,  helpdesk, CMS, and membership system. It installs places membership systems on mulitple websites and you control them from one central interface. This allows you to build one working prototype, and then clone the system for many different sites.

They do allow the sequencing of content depending on when a new member signs up. They also have an add on which allows you to send information to a fulfillment company.

This is in their terms of service "Goldbar.net reserves the right to change fees at any time, for any reason at its sole discretion. " - a bit scary...

They also sell a video called "Membership Superstars" which I found to be more of a long sales letter than a how to on membership sites. Useful if you are interested in their software as it explains how it can be used.