I would be extremely interested to see if you make any money out of this. What are you including in the pack? Is it just the buttons.css, which you can easily download from your site already? I'd be a bit more impressed if it was more tightly linked in with the kuler api - so that you could enter any theme name and get a set of buttons.
http://webcache.googleusercontent.com/search?q=cache:wznsub_...