The current equivalent of the Stealth is the Phantom. I'm not sure what the current MSRP is, but at a guess I'd say $2K. That places it solidly in the middle price range for bents - at the low end for Lightning but definitely not a cheap boat anchor. Lightning makes nice bikes. Since the Stealth is old enough to be discontinued, a good starting ballpark guess would be half price, or $1K.

Like with any bike, make sure it fits you.

edit: the bike could be quite old, in which case you might start the bidding at closer to $400-500. See if it has a 7-speed cassette or something more updated.