I agree that 16,000 miles is nothing on that diesel.
But can't say much for the price. I bought a new 2012 F350 King Ranch FX4 SRW with 5 miles on it last July for $14,000 off the sticker price. Neighbor bought a new 2012 F350 Lariat FX4 DRW the same day for the same $14K off. That was the standard reduction off sticker for all that dealer's superdutys at the time, which basically meant selling at a little under invoice and plus all rebates available at the time.
Right now that dealer is advertising $11K-$12K off sticker for new 2013 Superdutys. Check all your local Ford dealers web sites to see what they are offering.
They are mighty nice trucks.