If they are anything like the VW Autostick then the lower value is because
the transmissions were said to be trouble prone and very expensive to
rebuild.  That was 10 years ago.  Now some of those tranny parts might be
made of unobtanium (that means they cost $"infinity" because you can't get
them new).  I would check around to see if anyone still rebuilds these
transmissions and talk to them first.

Thanks,
Ken Wilford
http://www.vanagain.com
John 3:16
Phone: (856)-765-1583
Shop:   (856)-327-0027
Fax:     (856)-327-2242