Why sell the cow when you can sell the milk by the squeeze?
[link|http://www.curl.com/html/products/pricing.jsp?c1=46|http://www.curl.com...ng.jsp?c1=46]
<quote>
We charge commercial customers based on the volume of Curl content executed. If you would like to deploy Curl content in a commercial setting, please contact us at sales@curl.com. Our license agreement includes a standard fee and allows for volume-based usage discounts. Non-commercial users can deploy Curl content at no charge.
</quote>
I remember actually seeing the price somewhere but I can't find it at the moment. It was quite expensive IIRC.