The manual transmission can last a long, long time, but as mentioned, the slave cylinders go bad on them, so while you won't have to worry about replacing the entire transmission, you can plan on replacing clutch discs and slave cylinders, which do require drivetrain and transmission removal.
The automatics tend to go out and need rebuilds, so factor that in if it's never had service. Easy driving and no towing, along with keeping the engine cooling system maintained, and the ATF as well, will extend transmission life.
First Gens in general can last 300,000+ with regular maintenance, so if it's in real good shape and doesn't need work, $1500 is fair, especially if it's 4x4 and a high trim level like an Eddie Bauer.