I'm not really commenting on the price chosen, but the choice to charge for it. I've also created a jQuery plugin or two. I released it for free and now spend a reasonable amount of time answering questions about support, implementation, etc.

For some reason in my mind I had always assumed that open source type things have to be done for free: the building, the support, etc. Seeing someone doing something others helps put that in perspective.

Or, in short: I wish I was smarter about it and more business-savvy.