I would buy it in a heart beat over a 50,000 mile truck of the same age. Probably will last longer and be way cheaper. I did the exact same thing one time, I bought a 95 maxima with 327,000 miles in 03 and my budy bought a 97 maxima and my maxima had way less issues even though they were the exact same car, his had 70,000 when he bought it and would beg me to trade him.

The thing is the engine stays warm longer and gets less sludge and condensation and sees less rich mies that cause fuel dilution, also someone who depends on there car like that generally takes much better care, also they are usually highway miles and the trans has to execute less shifts than a low miles city driven car. Also since they are usually driven on the highway in order to rack up that many miles that fast they usually hit less pot holes, and turns less corners so suspension is less worn on. There are a lot of other factors in play that benefit a super high miles car. Useing miles to value cars is a big scam, the actual condition of the car can be based much better off other factors but I don't really care as I can get some great deals on some good cars when they value them that way, I paid 1/2 of what my buddy did on the maximas in the above example and a lot less on repairs.