I'm currently writing an eBook teaching Backbone.js in CoffeeScript, of about the same length as Recipes with Backbone. I'm still mulling over how to price it. Does anyone want to make a guess about the potential size of the market? Am I correct to think, the bigger the market, the more cheaply I can price it and still make a bit more than minimum wage for the time I'm putting in? Any further comments or suggestions about pricing are welcome.