It's also important to find recent calibration stickers on them. It indicates they have been taken care of and properly calibrated, even though automotive work doesn't require it as much, it is important to see on a used meter and helps the value.
Buyer beware with calibration stickers. Unless you are 100% sure they were placed on the meter after a real calibration they ain't worth the paper they're printed on. They only cost a few dollars a roll.