How marks work

1.One method for everyone

Every car in every garage is valued by the same published method — the Dream Garage Mark. Nobody gets a better feed; the edge is in the buying, not the data.

2.Primary mark

The median of comparable sales: same model line, within ±3 model years, sold in the trailing 24 months, with at least 3 comparable sales. The archive holds Bring a Trailer auction results and — tagged by source — completed sales from Curated OVRLND, a curated dealership whose sold archive deepens the classic-truck families BaT covers thinly. A model line pools its variants — an SL500 and an SL600 are the same line (the numbers name the engine, not the car), while genuinely different lines (a 300SL, an SLS) never pool together.

3.The fallback ladder, always disclosed

When the primary set is too thin, the method widens in a fixed order — ±5 model years, then a 36-month window, then the marque-wide median, then the catalog reference value. Every rung needs at least 3 comparable sales, the marque rung included: with fewer than 3 sales anywhere in the marque, the mark falls through to the catalog reference rather than lean on one or two sales. Any mark from a fallback rung carries its basis in plain words beside the price — "From ⟨n⟩ real sales" when sales priced it, "Collector value · catalog reference" when the catalog reference did. And if any comp pool spans ten-to-one or more from its cheapest to its dearest sale, that pool is not one market, so the Mark steps past it rather than average two different worlds. The marque median must also sit within a third-to-three-times band of the car's catalog reference when one exists; a marque number wildly inconsistent with the reference abstains to it — and for a reference of $1M or more, that abstention yields no Mark at all rather than a pooled mispricing. The marque rung must also be relevant: it may only price a car when at least 3 of the sales in the marque pool are the car's own model line — with fewer than 3, the pool mostly describes other cars, so the rung abstains to the catalog reference instead of pricing one model off its cousins.

4.Sources, never blended silently

Every mark names its sources and comp count (e.g. "7 BaT sales, 24 mo", or "9 sales (6 BaT · 3 Curated OVRLND), 24 mo"). Provenance is stored on every archived record and carried through the comp pool to the label and the nightly integrity sweep. Two honesty rules ride along: a broker's displayed sold price may be its final asking price rather than a verified auction hammer, so broker sales are tagged as their own source and the method's at-least-3-sales medians keep any single record from carrying a price; and a live listing's asking price is never a comp at all — asking prices sit in the archive as reference data only, excluded from every valuation by type. The broker publishes no sale dates, so its sales are dated at listing (a sale can only complete after its listing); records whose dates were lost when the store changed platforms are archived dateless and — exactly like an undated auction result — never enter a trailing window. When a model has almost no sales history anywhere, it is flagged for review rather than quietly valued on air.