A few observations off the bat.
1. It is owned by a young gentlemen in the country
2. After market air filter
3. After market exhaust
4. Lifted
5. STI
All of this add up to work and ego, this truck has been rode hard since he has owned it. They have a great drivetrain but if something fails it gets expensive. With the above five reasons if you like it bring it to a garage so they can check the fluids for metal shavings and give it a full check. Personally i would be a little put off by it because i know there are plenty of older gentlemen that buy a diesel to move their camper and/or boat around a few times a year. That is just me though.