Set up a recurring payments button and drop the HTML into a page. The IPN does the rest. Its simpler than you think:
http://blog.awarelabs.com/2008/paypal-ipn-python-code/
If within your first month of operation you have customers changing subscription plans then worry about how to deal with it.
Don't solve problems you dont have yet. If you don't have customers yet you've got more pressing concerns.
Having gone through this recently, Im hoping to save you pain.
Set up a recurring payments button and drop the HTML into a page. The IPN does the rest. Its simpler than you think:
http://blog.awarelabs.com/2008/paypal-ipn-python-code/
If within your first month of operation you have customers changing subscription plans then worry about how to deal with it.
Don't solve problems you dont have yet. If you don't have customers yet you've got more pressing concerns.
Having gone through this recently, Im hoping to save you pain.