Data foundation

Condition grading: normalizing the least standard field

Condition is the field with the highest price impact and the lowest standardization. 'Excellent' is a claim, not a measurement, and it means different things on every platform.

Grade ladder
6

sealed, open box, excellent, good, fair, for parts

Price impact
up to 45%

spread between sealed and fair on the same variant

Comp rule
Stratified

grades never pooled into one median

One ladder, mapped from many vocabularies

Every source's condition vocabulary is mapped onto a single six-step ladder: new sealed, open box, used excellent, used good, used fair, and for parts. Mappings are explicit and inspectable, not inferred per listing at read time.

Where a source's grade is genuinely ambiguous — the common 'pre-owned' catch-all — the listing is assigned the conservative grade and flagged, rather than being optimistically promoted.

Description text is a downgrade signal only

Seller descriptions can move a grade down but never up. Disclosed screen scratches, missing accessories, battery health below threshold and repair history all pull the assigned grade toward the conservative end. A glowing adjective in the title changes nothing.

Grades are never pooled

Medians are computed within grade. Pooling a sealed unit with a used-fair unit produces a central estimate that describes no purchasable item and flatters low-grade inventory while penalizing high-grade inventory.

When a grade has too few comps for its own median, MarginMap says so rather than borrowing the adjacent grade's number.

Grade uncertainty is a reseller risk line

Buying at a claimed grade you cannot verify before purchase is a real, quantifiable risk. The evaluator carries grade uncertainty into the sale-side price assumption, so a deal that only works if the item arrives one grade better than described is visibly marked as such.

Frequently asked

Keep reading

Run one product through it

Open the workspace, search in plain language, and open the evidence drawer on the first number you doubt.