I would not have paid that much for it unless I saw it either freshly cut, or better yet, standing before being cut. I bought two trees around that size for $100 apiece the other day and they should be cut down next week. One is about 20" ABH with about a 12 ft clear log and some salvageable leaders, and the other is about 17" ABH with about a 20' clear log and a few salvageables.
I found out I can cut through 16 penny nails with the bandmill and keep on going to finish the log. Did it once, anyway. 3 nails in one walnut log-- I finished the entire log before changing the blade. The lumber was a little wavy toward the end, but I knew I was going to discount it for the nails, and so on anyway. Walnut is worth enough to risk a few nails, especially for a bandmill. I won't risk it for any other kind of wood, at this point, except maybe ambrosia maple.