There's a member here, mc2, who has (or at least had, I haven't seen any posts lately) an
incredibly huge collection of early Sunn gear; I think something like 5 2000S rigs, 4 or 5 smiley face heads and cabs, one of Leslie West's Coliseum T's, multiples of most
all of the "ultra desireables" etc. etc. etc... as well as a ton of very tasty non Sunn vintage gear.
I think mc2 was in NYC Metro, and did a
lot of buying and selling.
I don't know if that's who it is, but that's the first person that popped into
my mind when I saw the listing and read the description.
As far as the price, who cares what the
BIN is? Those are my favorite type of listings, if I see something I want with a BIN/OBO, I'll bid what I am willing to pay and forget about it unless I get a "Congratulations!" email from eBay; no temptation to chase things too high. I've actually bought gear off eBay for less than
half of the BIN price.
Granted, way more often than not I
don't get it, but what's the harm in trying? As the old saying goes "Nothing Ventured, Nothing Gained".