qualifier number + unit a measured amount

free-shipping threshold

The order-subtotal amount at or above which a shipping rate becomes free — the 'free shipping over $50' rule. A qualifier of `shipping_rate` (cardinality one), a numeral with a currency unit (reuses Currencies). Part of the rate's bundle (Google Merchant binds free_shipping_threshold inside the per-rate shipping entry): the threshold is meaningful only against the specific rate it waives. The realised subtotal comparison happens downstream; the pool declares the threshold's grammar.

Free-shipping threshold is a price, given as an amount in a currency such as USD or EUR.

It is a qualifier of shipping rate — it has meaning only inside a shipping rate statement, one per statement, never on its own. It belongs with shipping rate to fulfilment — one facet of a product.

It is answered inside every shipping rate statement, not as a standalone question on a kind.

answered with: №number + unit — a number paired with a unit drawn from an exhaustive unit vocabulary.
value domain: Currencies — the vocabulary its answers are drawn from.
qualifier of: shipping rate — one per statement — it has meaning only inside that host's statement.

Answered inside every shipping rate statement — not a standalone slot on any kind.