The dealer was trying to scare you into buying something from him. But lets put this in perspective. A $2000 supercharger is still cheaper than a $7000-$15000 car (Assuming he was a used car salesman) or a $13000-$30000 car (assuming he was a new car salesman). Ad in the negative equity you currently have in Alien II, you can see that even if you purchased a new SC, you still come out ahead!
All that asside, your SC should last a long while. I know of two members who changed their SC'* out--one to a FLOZ as an upgrade (ask Will about that), and one to a rebuilt unit due to low boost. Neither one of them had any catastrophic failure. It can happen if you don't perform maintenance on them, run them without oil with a pulley that is way too small, and over rev the engine consistantly, but it isn't common and chances are that if you do those things, the rest of the engine will fail first.
Tell that polyester suit wearing, money hungry, unscrupulous salesman that his claim is ludicrous, and that you would never purchase a car from a dealer that he works for.
Retired Moderator, The Bonneville Club www.bonnevilleclub.com
RIP Oldsmobile, April 29
1995 Bonneville SE Supercharged (Stock)
Current Mods: Dirty GYM Sock air freshener.