Surely the best way to 'help' an open source project is to submit code patches to the repository, rather than send them money? Also it looks like most of the money is going to be spent on designers and editors. If it's an open source book then why not just write the book then release the source then if it's good ask for designers/editors to work on it. Maybe some will do it for free. Maybe they will want paying, at which point fundraising would be appropriate. If it's not actually published as a printed book I don't see how the design matters, and if it is published then the publisher will be profiting from it so surely they would pay for design work themselves.