Buying a used car... How many cents per mile is a value? ?

Example: If you buy a car for $4000 dollars, the car dies after 50,000 miles of usage. You would have paid 8 cents per mile.Buying a used car... How many cents per mile is a value? ?
Buying a used car is not and has never been gaged by how many cents per mile. In all actuality this doesn't even come close to be a fair criteria to judge the value.

More often than not the amount of miles is only one portion of the equation by which the value should be judged.

The previous owner, how often the car was serviced at what intervals, and probably the most important where it was drove.

City or Highway.

Many cars that are driven in the city could be junk at 70,000, where on the otherhand I have sold 2 vehicles after 250,000 that were 90% highway driven and are still on the road today. But I serviced them religiously at 3 to 5 thousand miles and kept air in the tires.