Which model is it? VX-I, VX-II, VX-III etc? Tube size? Reticle? Paralax adjustable?
In my opinion Leupolds are much under rated. I've had good service out of mine over the years.
The 30% less than new used to be good advice but as new prices have risen dramatically over the last couple of years, I suspect 50% may be nearer the mark (sadly, if you are selling).