I'd let it ride for a few days and then give 250 for it unless it's something you just really want for some reason, 3 bills ain't bad for a 215. Just make sure it has the right speakers and they both work or if they've been replaced somewhere along the way, know what the replacement is and make sure they're both the same.
+1 for will. it's a pretty good cab (early 90's were good times for ampeg cabs imho) but they're not hard to find, and i would think they're especially not hard to find in a city like seattle.
