Regarding the question of economical cross-references for the expensive
Dealer oil filters for your Vanagon:

The two original oil filter suppliers to Volkswagen are Mann and Mahle. I
stock them under the actual manufacturers' names, rather than the Volkswagen
name, for much less than the dealer price.   I variously ship either Mann or
Mahle depending on which I can get at a better price at any given time. They
are interchangeable in terms of quality, and both feature the correct flow
characteristics for the Vanagon engine. Not all aftermarket filters do.

For the watercooled Vanagons, they are $4.29 each.  For the aircooled
Vanagons, $3.99 each. Minimum purchase is 4.

- Ron Salmon
  The Bus Depot
  http://www.busdepot.com