Why these sizes sell out first

Ask any boutique manager which sizes they reorder and the answer is a narrow band: 37, 38, 39. Production follows the same curve. It is efficient, it is correct on paper, and it leaves two groups of women permanently underserved — the ones below the curve and the ones above it.

In resale, that shortage inverts. A 41 in an Hermès Chypre does not sit; it is bought within days, often by someone who has been searching for two seasons. A 35 in a Chanel ballet flat behaves the same way. The middle sizes, meanwhile, arrive constantly and compete with each other.

Scarcity is manufactured upstream

Houses do not make fewer 42s because fewer women want them. They make fewer because the marginal pair carries the same tooling and leather cost as a 38 and sells more slowly at full price. What is rational for a boutique becomes a decade-long drought for the client.

What this means if you are buying

If you wear a rare size, speed matters more than patience. Set an alert for your brand and size rather than checking the collection; the pairs that suit you rarely last a week. If you wear a middle size, patience is the advantage: you will see the same reference more than once, and you can wait for the right condition grade at the right price.

What this means if you are selling

A rare-size pair in Excellent condition is worth considerably more to us than a mid-size pair in the same state, and we will usually buy it outright rather than take it on consignment. If your closet holds a 35 or a 41 you no longer wear, it is the single most liquid thing in it.

Rare sizes are bought by women who have stopped hoping and started hunting.