Methodology & freshness
How we source
our price data.
A price signal is only worth as much as the method behind it. Here is exactly what our numbers are, what they are not, and how to read them.
Read this first
Our signals are built on observed asking prices from active listings — not confirmed sale prices, and not an appraisal of what a bag is "worth." A signal is a listing-opportunity read: how a given listing sits against comparable listings on the market right now. It is not investment advice.
Asking price, not sold price
During beta, what we measure is what sellers are asking across authenticated listings. Confirmed transaction prices are not reliably public, so we do not claim them. When we can add a compliant source of completed-sale data, we will label it separately and clearly — we will never quietly mix the two.
Where the data comes from
Live listings and links come from marketplace APIs — at launch, primarily the eBay Browse API, which also lets us surface listings covered by Authenticity Guarantee on eligible items. We prioritise authenticated listings during beta. As we add further authorised sources, each one is listed here with what it is permitted to be used for.
The comparable-median method
For each bag we define a precise entity — house · model · size · material — because those attributes materially move price; a "Loewe Puzzle" is not one price series, but a Small Calfskin is. We then take the current comparable listings for that entity and report:
- the comparable-listing range (low to high),
- the comparable median, and
- where a specific listing sits versus that median (for example, "22% below comparable median").
That percentage is a signal of opportunity against the current market of listings — not a claim about fair value, resale value, or future return.
What's included in a price
We work toward an all-in view: item price plus shipping, and estimated tax or duties where they apply. Where a figure is item-only, we say so. Currency is shown in USD during beta; cross-border and currency effects are noted rather than hidden.
How fresh it is
Every signal carries a refresh date. During beta the per-bag trend shown is illustrative and clearly flagged — real tracking begins once daily collection starts, and a bag only shows a genuine multi-week trend once it has accumulated enough real observations. We would rather show "tracking begins soon" than a confident line we cannot stand behind.
Confidence & coverage
Not every bag has a deep market at every moment. When comparable listings are thin, we say the confidence is low and show fewer conclusions rather than more. When there is no matching listing at all, we tell you that plainly and keep watching on your behalf.
Why you can trust the signal to be neutral
We earn a referral fee when you buy through a link. It never changes which listing we surface: the cheapest genuine, authenticated listing wins regardless of who pays us. If we cannot evidence a claim with a dated, real listing, we do not make it.
Corrections & takedown
We want to be an accountable information service, not an opaque affiliate layer. If something here is wrong, tell us and we will fix it — usually within a few business days:
- wrong bag metadata (model, size, material, generation),
- a stale or clearly mispriced signal,
- a broken or mis-targeted listing link,
- a trademark, image, or copyright concern from a brand or rights holder,
- a data-source or attribution concern from a marketplace.
Reach us at corrections@1828couture.com. Brands and marketplaces can use the same address for source or trademark matters.