How can I determine what a particular discontinued model is worth?

[uncleknife]

I am not going to name the long discontinued Spyderco model, as I don't know if this is out of line or not, but I could not find any current threads on another forum, so I don't know if making a trade request is in the right ballpark for another model or not.
Any suggestions?

Thank you in advance.

[SG89]

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