i spent 15.5k for mine with half the miles and lost the engine 3 months later.
I have 7k in it to get a used engine and other issues to get it road worthy in maryland.
this was all before the economy went south and diesel went north!!!
i would do lots of research about what to look for when buying a truck with that many miles. it can be very risky. there are plenty of threads on the org to read through to help guide you.