How do you judge value ?

[Crusoe]

If you were to sell it, how much would you get willing to accept?

If you were to buy it, how much would you be willing to pay?

[NancyJohnson]

On the OP, my thing was Thunderbirds.  Nobody (at that time) was particularly interested in them, so you could pick them up for £750-£800.  So I did.  Lots of them.

 

When time came to start moving them on, more of a demand, so it was easily possible to turn a profit.  Playing the long game.  Do your diligence.  There's several resources out there (Reverb/Talkbass/eBay/here) where you should be able to ascertain the current market price even if the instrument is a short run model.

 

Thing is, the market shifts.  Look at what you can pick up a used Warwick for nowadays.  Bonkers.  There's too many basses/guitars being made and my gut feeling is that less and less musicians (those darn kids) are particularly interested in the nuances in more expensive/special edition kit.  A Jazz Bass is a Jazz Bass, irrespective of how much Fender try and sex them up.