Per your description of the bike with its top end Spidel equipment, I would say around $650 to $700ish max., considering the depreseed economy. Closer to maybe $800 if the bike and components are very close to mint/NOS. But I suspect it could reach a bidding price of $900 or higher easy during better times.
Maximum value for these higher model 80's bikes depend on how original they are and their condition, of course. If the components are what the bike might have come with from the factory, the price/value will be much higher than a "Frankenbike" even if the "upgrade" components might all be period correct, unless the substitue components might be super valuable, unobtanium pieces (Unfortunately, Spidel stuff, good and rare as they are, haven't quite reached that status) which will make it that you will be buying the bike more for its components to harvest and transfer over to a more expensive frame or sell for profit.
JMOs
Chombi