Okay well I just sold two ballscrews for 11 bucks each, same guy and all. I advertised them as what i believed them to be, 5/8 ROLLED ballscrew (rolled is pretty cheap, about 1.25 per inch). But i looked very carefully, and had another person look. It sure did not look rolled, but i did not think it was ground. Until i came across a picture of a true ground (very expensive and valuable) ballscrew. And these look identical....
So i think that what i sold, the guy believed it was 5/8 .2 rolled.
But now I am thinking its 16mm OD with a 5mm pitch, precision ground. The latter is MUCh more valuable, probably 5x the price.
So what do i do? I was thinking i would email the guy, let him know whats up. If he wants his money back, i will refund entirely. If he wants these screws, i will sell them to him at the same price.