Is this a good price for a 2004 Chevy Silverado with this mileage?

[Snowbunnyx14]

2004 Chevy Silverado with 120,000 miles on it.
They're asking $6,000.
It also has a nice system, black rims, and blue lights.

Btw- this will be my first car.
Is it worth the price, even though it has so many miles on it?
How much longer will it run?
How long do Chevy's usually last?

Thanks.