I don't think this is a bad idea, honestly; as long as the backers get something out of it, there's no harm in asking for money (a straight-up charity model would be a very bad idea for publishing, I think), and there's a community feeling that's beneficial for both the publisher and the reader. I'm surprised more publishers haven't tried to adopt an NPR membership model—it would be annoying to get a ton of pledge drive e-mails in your inbox from a bunch of different publishers, but the primary hardcore reading audience has already proven that they respond to that kind of appeal.
(Full disclosure: I'm already a backer of this project for $40. I like Wertz's stuff a lot, and I'd like to own autographed books by her as part of my permanent collection.)