DAP has a plugin system that can be activated when a user is added to a product (when they buy) and also when a user is removed from a product (when their access lapses due to cancellation or non-payment). It ships with plugins already for GetResponse and MailChimp - that adds a users name and email address to those mailing list services. I need an equivalent written for XenForo that registers the user with their name and email address.
If the user cancels their membership via DAP - the user should be moved to a specified usergroup in XenForo.
I've had a look at the GetResponse plugin that DAP ships with. I'm not a programmer, but it doesn't look overly complicated. Its only 132 lines long including comments - but I suppose the 'difficulty' of the project would be more determined by the XenForo API.
If you can quote me for this work I'd appreciate it. Similarly, I think this would be a popular product if someone wanted to develop it themselves to sell. Currently DAP only integrates with VB - XenForo integration would be really useful. Otherwise I'd consider paying for the time it takes to develop.
Please let me know if you can help or if you want more info on the plugins that ship with DAP and see how it all works.