Yup, all depends on maintenance. The two vans in my sig were bought from the local city van pool fleet. The '90 was bought used by the city from another city van pool system while the 99 was bought new. Both were fleet maintained up until I got them. The 90 has (they said 250K), but I found a sticker and did some math.... I think it only has 155K. The 99 just turned 220K today.... already put 3K since I got it in Nov of 08.
A friend's father just bought a 99 F250 w/ just under 200K. He'll prob. end up keeping that truck forever (as his 94 PS).
The 77 KW in my sig says it has 9XX,*** on the odo.
and the engine says it was a 1977. So I'm not sure if it's the original or a rebuilt..... but it runs okay. I've seen older rigs selling for $25K..... but it was mint and you could do long haul with it still.
My old 83 F150..... I'd trust it driving all over the state. Left me in the field once, but it was the distributor going T/U (bushing gave out- was original distributor). Not the smoothest ride or the prettiest, but I'd trust it on a trip. Drove it to college in the late 90's.... and that was before the GV OD.
Some question the idea of 'dumping' money into in an older vehicle when the cost could be a significant portion of the vehicles value. The "you'll never get what you put into it out if you sell" is the argument.