Script or Host Service to sell 1 Download file at a time?

[gaybucks_chip]

or, if you have your own merchant account, or are doing something you can process with paypal, x-cart supports electronic download and automatically handles generating a unique URL for each sale that only gives access for a limited period.

[raymor]

We have a system which integrates with CCBill and other processors
for that purpose. Their system is of course designed for subscriptions,
but we work around that. A better system is possible if you have your
own merchant account.

Clickbank is a processor does single downloads. They aren't as polished
as CCBill, but they seem to work. http://www.clickbank.com/