Chad, I sell the coolant temp sender for the 1.9l Vanagon (83.5-85) for $30.  
This is a Bosch unit and screws into the thermostat housing.   The part
number is 025 906 041 and it is also used for 86-91 Syncro Vanagon as these
have the metal thermostat housing as well.  The 2wd 2.1l Vanagons (86-91) use
025 906 041A which I sell for $9.  This is a totally different unit and is
much cheaper than the earlier version.  Why?  I have no idea but it must be
cheaper to make for some reason.  I hope this helps you.

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