To my knowledge, the Ryan with the Robinson inlays is the most expensive "asking price" for a new guitar, don't know if it counts until someone buys it... Second would be the Robinson inlaid Santa Cruz, again don't know if it has sold... as far as most expensive "new" guitar ever
sold - I'm guessing it would be a Martin "One of a Kind" inlaid by either Larry or myself. The top $ one from me was the "Custom Cowboy" which was to commemorate 170 years of Martin guitars. It sold for just under 200K. Larry's "History of Flight" was well in the 100's as well but I don't know if it sold or not.
I think the most expensive celebrity owned guitar was Mother Maybelle Carter's guitar, I don't remember the amount ($450K???). Merle Travis' Martin Bigsby sold for an even $250K and I know the Carter guitar was more than that.
If you are talking "Value" it would have to be the Millionth Martin, they sold 100 "scaled down" copies of it for 6 figures each, the guitar itself would have to be valued at "priceless."
I've sold a few custom Leach guitars up in the pretty rare air but nowhere near the Ryan/Robinson collaboration.
Martin Custom Cowboy Headstock inlay
Cowboy pickguard, this shows the special "holographic" inlay for the mirror in the background using a thin veneer of MOP shell as "glass" The same technique was used for the "smoke" on the headstock. ( a technique dubbed by Dick Boak of Martin as "Smoke and Mirrors")
