It's a fairly unique engine. Very popular in Europe, but Kawasaki did absolutely NOTHING to sell them in the 'States- despite the fact that most magazines liked them much more than the new Bonneville. After test riding a Bonnevile- I was forved to agree. One thing I think hurt the W is the stock tank looks like a slice of cheap wedding cake. At any rate, most folks seem to think it was a reprise of a model that was very British looking in the late 60's (can't remember the model) Who knows. I just like the way it rides and sounds. Very nice size for my stubby legs.
Not many were sold here, so they are few and far between. Seems like a good, low miles example might go for around $4 to $4500? There's a Yahoo Group you might check in with and tell them you're looking for one. That's how I found mine.