True when any of the listings has a paid line for this attendee — a gross sale leg in the row's ledger_event_group (a sale leg's amount is always > 0, so its existence is exactly a non-zero projected price_paid; a refund keeps the gross leg, so a refunded line still reads as paid). One query over all the IDs, read from the live ledger rather than the edit form's submitted key (a stale/missing key can leave it null), so a recorded payment is never dropped onto a fresh quantity-0 row. Callers pass a non-empty list.