Air Arms Owners Club

Hi all
I'm thinking of selling my MTC viper 6-24x56 IRS scope.
This scope is in perfect working order but has been used for hunting and has some light scratches and slight marks on the turret wheels.
My problem is I have no idea what these scopes are selling for 2nd hand.
Has anybody any idea of what Ishould ask for if I decide to sell.
cheers
Kevin

condition is key. if in good condition for age, i tend to work on 60%-65% of price new.

Thanks Gary