This is an old E-mail adress so I don't know if it is still valid but 4-5 years ago he sold false maps @ $12 ea. mailto:asalzberg@nyc.rr.com along with several other species.
East bay vivarium usually carries them but is currently sold out, they do have map turtles @ $20 ea. though http://www.eastbayvivarium.com/pricelist/turtleslist.html
You might also place a wanted ad in Kingsnake.com