Tough to say, because so many of my guitars have been gotten in trade, and it gets hard to quantify price when you're trading something you traded for. I guess the candidates would be this:
There are some spectacular instruments in this thread.
My Lowden is the most spendy guitar I own by a wide margin. I bought this new on the day it was delivered to the store in 2003. I just happened to be in the store when they took it out of its case, it was never even hung on the wall. They had a financing program that made an otherwise insane purchase attainable so I pulled the trigger.