Sorry to hear they're flakey sellers , hosman .
The one thing I've seen , from your posts , is the fact that they are consistent folks .
Consistent at being inconsistent .
If you did make the trip down to Portland , is there something that would honestly make you think they'll be home / will show up ?
If it were me , in your boots , I'd send them a polite email - stating that I'd trusted them to show up in Washington state and was sorry that they could not make the trip , as promised .
What with no-showing , lack of communication & such , I'd not bother dealing with them .
Portland is a big city & they should be able to find a local buyer there .
The one other way to deal with them , perhaps , is dependant upon you having a friend down in Portland , who'd be willing to pick up this item (maybe the friend could get it for less , too - sorry - I'm in touch with my inner cheapskate on this deal) .
But that's just me & my opinion .