We anticipate authors will be able to raise several thousand dollars for promising book projects. Very promising ones certainly may raise $50K or more.

Crowd funding is proving to be a very powerful fundraising model. For example, the record, so far as I know it, is currently $190K for an iPad stand listing on Kickstarter.com:

http://www.kickstarter.com/projects/jay-design/padpivot-lap-...

Edit: Also, successfully raising funds is just the start, as this would be a great indicator of ready market demand for the book.