Check out the "sister site" that Dave created, cubits.org .
See if it might meet your needs.
edited to add...
Sorry, I just clicked on your gofundme page and realized you needed to put an app on your website to coordinate buyer and seller locations... that's probably beyond the scope of cubits, although it wouldn't hurt to drop Dave a note (tree-mail on this website, c-mail on Cubits) and see if you could get his input/advice. He's "Dave" on this website and on cubits.
