All depends, Doc. This seller doesn't provide any information on the wagon at all. Bad pics, too. Could be a great wagon. Could be a dud. IMO, since CL ads are free, and take maybe 5 minutes to post up, I'm thinking we've got a real lazy seller here. If I had to guess, I'd say you will probably find a few issues with this Olds, and it's probably in reality a $3k wagon (or less) $5,500 would be on the high end for one of these - in 'very good' condition.
I can see that it is a 6-passenger (2-seat) wagon at least... or at least it appears so, because I don't see the rear vent window on the cargo area window.
That is what I was thinking, too. I suppose the price is pretty much a starting point until there is eyes on steel.