I'm of the opinion, the best value in the Duramax would be the '06 and classic '07 models. Transmission is bullet proof. Some guys are claiming 300,000 + miles, but those guys are acturally maintaining the truck and not using it as a car (short daily trips in town). Best fuel econ would be '02 - '03 (LB7 motor), the LB7 had injector problems at right around 100000 miles depending on maintinance, covered under warrenty from GM. I agree what Dutch said, personally, I'd go with a classic '07 myself.  Check out craigslist around a 5 or 6 state area - seems to be some very good pricing (for Mn at least) . . . .