I've been flipping bikes since 1912. The only way to make money is to pay nothing, part everything out on ebay, and then use the frames to make wrought iron fences and the forks to make garden rakes. I wouldn't pay more than $5 for the lot. The market is soft right now, and you've got to know when to hold 'em and know when to fold 'em.
Am I doing this right?
Good luck with the charitable endeavor.