I do agree with calbashmc that the extension store could be more informative. I have purchased a couple of extensions and did find a lack of documentation, and that the description on the product did not match to the the extension could do. I did report the issue to Algozone within a couple of days of purchase.
Nothing has happened in the over 30 days since.
On the extension store - if you click on the About Marketplace there is some information - including this about Support and refunds.
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Support
Each paid extension comes with 15 days support and money back guaranty.
Free update and upgrade is offered if your extension update becomes available.
To conduct support please follow the link on the bottom of the market place page
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Perhaps that will help you some calbashmc. And I believe Algozone has joined the board - perhaps a posting on the board with your requests might be answered by them - that could help us all decide what an extension can really do and add instructions as to how.