The advantage of buying live is that you can ask. Here is what to ask for.
The five things to request
The size tag, in focus. Not the box label — the tag inside the shoe. They should match, and a seller showing only the box is showing you less than you asked for.
The sole. Wear patterns tell you how much they were worn, regardless of what the description says.
The toe box, straight on. Creasing is the single most visible condition factor and the easiest to hide at an angle.
The heel counter. Collapse there is permanent.
The box, if it is claimed. Including the label.
What a refusal means
Treat it as an answer. A seller who moves on rather than showing you the sole is not necessarily hiding something — but you are now bidding on an unknown, so bid like it.
On fakes
Ask the seller what they know about where the pair came from. A straight answer — including "I do not know, I bought it in a lot" — is more useful than confidence.
Do not rely on a blog post, including this one, to authenticate a pair. The tells change with every production run and anybody telling you a single reliable test is selling you certainty rather than information. If authenticity is the whole value, buy from somebody who will stand behind it and use the protection that covers "not as described".
Size
A stated size is not a measurement. Different makes run differently, and a sneaker that fits in one brand does not in another. If fit matters, ask for the insole length rather than trusting the number.
Questions people ask
What does deadstock mean?
Unworn, with its original box. More condition words.
Is the box included?
Ask — do not assume. For a deadstock pair the box is part of what you are paying for, so it should be stated rather than inferred.
Can I return them if they do not fit?
Fit is a change of mind, which depends on the item. Not as described is different and always covered. How returns work.
What if they arrive and they are fake?
"Not as described" — raise it on the order within seven days of delivery.
More: buying safely.