I say go for it!  At $1000 this is a great price for either a Fuel Injected or
a diesel pickup (although the diesels are the more desirable of the two).  My
first car was a sweet '81 VW Diesel pickup with a cap.  I still know who owns
it and want to buy it back.
Things to look for:
A five speed is most desireable for these pickups and AC on these is pretty
rare (desireable).  Both of these options on a diesel and this truck is worth
some money if the body is nice (around $2500).
Check the shock towers under the hood (this is usually where they rust first)
and also around the rear window for rust.
I have owned my '81 Diesel pickup and an '82 Fuel Injected (dressed up with
some Porsche parts and gold alloys - the guy even painted "Porsche" in gold
lettering on black plastic and covered the Volkswagen on the tailgate!).
My dad has owned an '80 diesel pickup (80s are rust buckets and the 1.5l
diesel motors are not that great) and presently has an '81 diesel pickup.
We are diesel fans as well as Vanagon fans.  (I even have a diesel Vanagon in
the yard now, but only for parts).
Ken Wilford
Van-Again
John 3:16