Buying second-hand only works when you can see every ball's real condition and know which discipline it suits. Ask sellers to show defects rather than hide them with polish.
Questions to ask
Confirm brand, age, playing frequency, cleaning method and reason for sale. Request marking photos, close-ups of chips and a rolling video on a level surface.
Set compatibility
Match diameter, weight and quantity to your table's rules. One ball from another series can rebound differently. Clubs should prefer a consistent model throughout the set.
Payment and returns
Arrange inspection before payment or a short return window. Put the ball list and declared defects in writing. Avoid full prepayment to an unverified seller.