I would very much like to purchase one of these plants. Do you know where I could find one for sale?

Caladenias are reputed to be very difficult to cultivate. I'm not sure that Caladenia lobata is propagated for sale, and as you surely know it's forbidden to dig it up from the wild. Anyway, you might contact the "Association of Societies for Growing Australian Plants" (ASGAP) at http://farrer.riv.csu.edu.au/ASGAP/