It's a great pin, I've owned mine for 16 years now! But I'd say, "Don't buy it". PM me where it is and one of my friends will take it off the guy's hands. Just kidding, sorta.
But really, the cool shot is the upper ramp shot. It increases the playfield multiplier which makes every shot or multiball, or video mode score higher. It is timed so if you don't keep hitting the shot, it starts decreasing again.
So I'd say buy it - wait, don't buy it!
Al