Prices and valuation

Select the sources you use

In Settings → Price sources, enable the markets displayed on card pages and in Android. The installed sources are Cardmarket (EUR), TCGplayer (USD) and CardNexus (EUR). Availability varies by game, printing and configured API keys.

When several sources are enabled, select a Main price source. It controls collection values, catalog ranges and price sorting. If a game does not support that source, Zukan uses its first supported source. A supported source with no quote for a particular printing does not imply that every other market is searched for a replacement quote.

Sources and markets are distinct: catalog APIs can supply a Cardmarket quote without Zukan calling Cardmarket's authenticated marketplace API.

Unit price and total

For an owned variant:

1. A manual price takes precedence when present, including zero.
2. Otherwise Zukan uses the latest non-null trend quote for the printing and finish from the game's selected source.
3. If neither is available, the item is unpriced.

Item total = unit price × current quantity.

The item editor treats the manual price as a unit amount. Clearing it restores automatic pricing. It is a valuation override, not a purchase-price field or a realized profit calculation. It has no stored independent currency: it is interpreted in the game's currently selected valuation currency. Recheck manual overrides after changing the main market.

Source quotes are per printing and finish, not per condition or owned-card language. A low-grade or rare localized copy can therefore differ substantially from the generic market value.

Currencies

EUR and USD are never added together or converted automatically. The value API returns separate currency totals. Global history and Finance omit games whose valuation currency differs from the main report currency and can identify those other currencies. Select a game to inspect its own currency context.

Dashboard and Finance

The Dashboard offers total value, most valuable cards, market-price movers over 24 hours/7 days/30 days, a value chart and recent changes.

Finance expands this with quantity, printings, priced/unpriced copies, average and median values, period changes, history, most valuable items and breakdowns by game, set, rarity, condition, language, finish and price band. Figures depend on available quotes; an empty or unpriced collection cannot populate every chart.

Movers use market price changes multiplied by copies held. A manual valuation does not alter the market trend itself. Missing comparison history is different from a measured flat trend.

What historical charts mean

The historical curve prices current quantities with each day's latest known quote. It does not reconstruct how many cards the account owned on that date. Adding an old card today can change the displayed value of earlier dates.

Current manual overrides are applied across the historical curve where the reporting path includes that game. The chart therefore is not an immutable audit trail and is not a record of deposits, purchases, sales or portfolio performance.

Snapshots normally accumulate from synchronization; complete historical market data is not automatically downloaded retrospectively. Older superseded quotes for printings with no collection item anywhere on the server are pruned. A collection row, including one at zero quantity, affects that retention test.

Missing or stale prices

Check the printing, finish, main source, quote date and latest price job. Some regional catalogs have no built-in automatic price source. An optional source may require a key or lack a matching product identifier. Refreshing prices cannot create a quote that no upstream source provides.

Implementation references

• backend/app/services/collection.py
• backend/app/services/prices.py
• backend/app/prices/base.py
• web/src/pages/Finance.tsx