Besides the new edition of 50, there are a small number of proofs available in varying ink colors and papers (info on the RRT page).
The current block of five released prints (#41-45) is priced at $700 each.
UPDATE (July 20): The #41-45 block is sold out. We are now releasing #26-30 at $750 each.
UPDATE (July 21): One print sold of #26-30 block; four remain.
P.S. If you're in Hoboken, stop by Right Angle Framing at 320 Washington Street (bet. 3rd and 4th). A Railroad Town proof, elegantly framed by the shop's Pablo Godoy, is on exhibit in their window. And it's for sale — ask Pablo.