The generic O2 sensors (made by Bosch) are every bit as good as the exact
part except that they do not have the connector. The reason for the high
price is low sales volume for all the different types of O2 sensors WITH
connectors. NAPA may only sell 3 Vanagon O2's a year but sell 50 generics.

To make the generic work you will need to cut and SOLDER the wires. Remove
the old sensor and lay it out next to the new generic one. Make a cut in
both so that the same total length from the end of the sensor to the
connector is maintained. Use the old connector and the new sensor. First
slip on some large heat shrink tubing over the wire bundle, then slip on
some small heat shrink tubing over each wire (about 2"), Solder the wire,
Shrink the small tubing, shring the large tubing and its done.

PS: Don't use electrical tape. It will let in water and corrosion will
degrade the O2 sensor signal.