Data Methodology

What our prices represent

Sokumise tracks observed reference prices from Japanese marketplace listings (primarily Mercari and Yahoo! Auctions), not confirmed sold prices. We use terms like Japan Reference Price and Observed Price Rangerather than “Market Price” or “Sold Price” unless we have sold-listing data specifically.

Median, not average

We display the median of observed listings, which is more resistant to outliers (a single mispriced or bundled listing) than a simple average. When we exclude outliers, we say so.

Sample size and confidence

Every price includes the number of observed listings behind it. Prices based on very few listings are labeled as lower confidence. We do not smooth this away — a thin market is a thin market.

Exchange rate

USD conversions use a daily static exchange rate fixed at build time (currently ≈ ¥156 / $1), not a live rate. If the JPY/USD rate moves significantly between our daily updates, displayed USD values may lag the live market rate slightly.

Estimated Landed Cost

The Estimated Japan Purchase Cost panel combines:

• Proxy handling fee ≈ ¥500 flat (Buyee-style, per item)
• JP domestic ship ≈ ¥800
• Intl shipping varies by category (small tracked parcel for cards, boxed parcel for figures)
• Duty $0 assumed under US Section 321 De Minimis ($800); not estimated above it

This is a single unified calculation used across every Sokumise page — Japanese and English — so the same card shows the same estimated total everywhere on the site. It is an estimate, not a quote. Actual proxy fees, shipping rates, and customs treatment vary by service and shipment. We assume no import duty under the current US Section 321 De Minimis threshold ($800); above that threshold, duty is not estimated (we do not invent a number).

Market Signal (Ana Score)

Market Signal describes observed market conditions (trend, liquidity, stability, cross-market gap magnitude, data confidence). It is not investment advice and never invents US prices. See Market Signal (Ana Score).

Charizard showcase (set identity)

The English showcase for Charizard ex SAR (#201/165) uses set-scoped observations only. Sold and active listing medians are never blended. We never copy the mixed Charizard hub average into that page. US references stay empty unless title-filtered eBay (or TCGplayer) rows exist — we do not invent US sold prices.

What we don't do

• We don't inflate or manipulate price gap calculations.
• We don't treat Market Signal as a review or rating of the card itself.
• We don't claim any price is a guaranteed purchase or sale price.
• We don't invent US sold prices to fill empty comparisons.