What is the lowest cost micropayment gateway for multimedia authors to sell their content online?

Question From User - Answers in Comments.

Subject tags: International micropayment gateway for selling content online

Dear
* support @ http://smallbusiness.yahoo.com/contactus/email_us.php
* interested peers at furl.net,
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I write this question as a public mail/posting to maximize the benefit for all people interested, giving you the opportunity to answer at furl.net [too]. Who knows the lowest cost solution for multimedia authors to sell their content via the web?

Thank you
f/t
PS.: Let's amplify each other's light.