The useful question in this category is not "what condition is it in" but "will it do the job".
Ask the specification
Bats — size, weight, grains, whether knocked in. Rackets — grip size, unstrung weight or weight class, current string and when it was done. Shoes — the size measured inside, not the size on the label. Weights and plates — bore diameter, actual weight, coating condition.
A seller who answers these quickly is a seller who plays.
Then ask about repairs
Re-gripping, re-stringing, toe guards, re-glued soles, replaced cables and bearings. None of these is a problem; an undeclared one is.
Ask directly: "Has anything been repaired or replaced?"
Then ask to see it used
Not a full demonstration — just the frame flexed, the joint moved, the cable pulled, the bat tapped. Thirty seconds of the thing behaving like itself.
Shoes and anything worn
Ask for the inside measured, the sole, and whether there is a smell. Sports shoes are the single most returned item in this category and it is almost always one of those three.
What protection covers
A specification that is materially wrong, an undeclared repair, damage not shown, or a different model than described: not as described, seven days from delivery.
Normal wear that was described is not.
Questions people ask
Is second-hand gear worth it?
Very often, and especially for growing children and for anyone starting a sport. Buy on specification rather than on looks.
How old is too old for a bat or racket?
It depends on storage more than years. Ask how it has been kept.
Can I ask for it to be weighed?
Yes, and you should. Stated weights are frequently the label's rather than the item's.