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I'm going to set up a website to sell files
I need to allow the module to be downloaded after paying.
This is a support form to help people with coding question.
What you are looking for is a commercial solution, I recommend looking for a company or freelancer who can guide you.
Or if you really want to do it your self I suggest starting here:http://drupal.org/node/1074360
From there you can create your own module. Your module probally needs some access control that manage who has access to whih files.
If you get stuck on certain code we can always help you out offcourse!
take a look at http://drupal.org/project/ubercart
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