I think there is a value kick for Pre-16s as opposed to the model-marked guns, but that may be just a personal bias. I paid just under $3000 for a really good 1949 gun with box last year -- no tools. A NIB 16-2 with box, tools and docs ought to be about the same in my opinion.
But we're talking about serious scarcity here, so I guess it depends on how many other people are going after it and how motivated the seller is to take some value out of his holdings. If the seller wants four, that's probably too much unless you are looking at the long term picture. The value will get there in not too many years, I would guess. But that would be a high price now.
In short, I would jump on it at 2500, let it go by at 4000, and consider it seriously at 3000-3250 -- assuming I had anything left in the acquisition budget after the one I bought last summer.