That bass was $1000 new in 98, not $700. I bought one. And I shopped around (and haggled) a lot at the time. Remember $1000 being the lowest I could get, but managed to work a case into the deal.
Warwicks, however, never having had any resale value for reasons unknown, also re-sold dirt cheap up until the late 2000s. I picked up a Fortress One for $440 around 2006. I remember seeing Corvettes go for $500 and less regularly - though that doesn't happen much any more. I'm gonna guess whoever sold it got a great deal, and then and then either just passed that deal along, or never followed up on the bass's worth.
My biggest Warwick score was as Stremaer Pro M at Guitar Center for $500. It was new, brand new but needed strings, batteries, and the knobs needed tightening. Whoever ran that store was an idiot. I bought it, and immediately resold it for $1000.
Great score! Congrats!