Paypal payments pro integration with drupal 6 I have a drupal 6 website which has the following workflow:


User logs into site.
User creates content through a custom module that I built.
This content is not a content-type, its custom content.
The user saves this content type, but cannot yet publish it.
User then hits publish.
He is asked how long he wants to publish the content for.
User selects from 15 days, 1 month, 2 months etc.
Depending on his selection he is provided a price for publishing the content for the interval.
If the user pays the amount shown, his content is published.
For each content page that he wishes to publish he will be provided the same options of selecting the interval and paying the price for the same.


I have three questions about this:

1: Are there any existing modules that would let me achieve this? (I did search and couldn't find any. My initial instinct was of-course ubercart, ecommerce etc... but I can't figure out how I would implement this specific workflow in any of these.)

2: If there aren't any existing modules for this, how would I integrate Paypal payments pro in my custom module? I can't find a straightforward tutorial anywhere. 

3: Is it possible to use the payment backends of any other modules. I know ubecart provides a bunch of different payment methods. Is it possible to use these modules without ubercart and call them in a custom module?
For a quick win on this on Drupal 6 I would use Ubercart, it ships with paypal pro integration. And http://drupal.org/project/scheduler

It uses conditional actions to assign roles, give access to file downloads etc. A simple, if perhaps slightly inelegant way would be to pass the node ID of the unpublished content to a product as an free value attribute, then upon successful purchase use conditional actions to publish it, setting an expiry date time on the object properties scheduler uses before saving the node. You should not give users permissions to use scheduler, and I'm assuming you have cron up and running.

Sounds bodgy, but you could get it up and running very fast like that. Check if you like it and still have time to look at other solutions if not.

Commerce module might also be good but haven't used it on d6