What does the shipping estimate on a listing mean?

Listings where the seller has entered box size and weight show a shipping estimate for your location, spread across the pieces: a $24 box across an 80-piece lot adds $0.30 a piece.

At checkout, shipping becomes its own line at the carrier rate — unless the listing says free shipping, in which case the seller covers it and there is no shipping line.

It is an estimate, not a quote. The checkout line is the real number.