The market shall tell, long-term...
All good points made. As I understand it, Bill's piece was one of the first original handmade Guardala pieces. Remember, in 1981, Michael Brecker was playing a Dukoff, and you didn't see him on the MB until 1984ish. Bill did play a Link on We Want Miles, but that was 1981, and all recordings since have been the Guardala. The Guardala models weren't established yet. Michael wanted more of a large chamber piece, and I suspect the piece Bill plays is smaller chamber, more baffle, but darker than a modern Studio or King. Roberto's Woodwinds website has a picture of the chamber on the signature piece, and that kind of confirms this suspicion, but you can't play a piece with your eyes!!
As you can tell I'm a big fan, I've been listening to Bill since picking up my first Miles Davis album, The Man with the Horn, in the 80's, I'm very curious how this piece plays, as I currently play Sakshama pieces, and have had Vigilante, original Guardalas, and other similar pieces in the past. I'm also curious who the craftsman is behind the scenes. However, like others, I can't justify the kind of price currently being asked. Maybe someday on the used market, or after production picks up...