$45 for a used scope, $85 to have it refurbished puts you not to far away from a brand new Redfield.
I bought a used redfield 3X9 for $50. I had some trouble with it about 2 years later. This is before Leupold bought them. I sent it to an outfit in Florida, can't remember the name. They were going to reseal it for $35. After they got it they said there was some trouble in the erector system and it was going to cost an additional $85 to repair it. Now I've got a $170 dollars in an old scope thats only worth about $75 in todays market. Never again. When your dealing with used scopes only Leupold is the one to buy.