Leupolds tend to hold their value pretty good around here. I would look up to see what they are selling for new then go from there.
Like...
The vx6hd 3-18x50 firedot is $1,350 right now on Euro Optic.
I'd probably start at $1,100 then go from there. If you want to move it fast. Start off at $1,000 then go from there.