i used to own one of those bikes, the trouble with the triples is that the seals go hard and the engine can get smokey so they are a bit of a trial to keep running nicely but on the other hand they are much sort after, there is a kettle club, surely the best place for valuation/advice. i agree with ebay being a market value but if you were looking for a gt 750 that wouldn't necessarily be the place that you would go, it being a classic now.
sorry you lost your dad Wyle87. why not keep it, i would.