If a standalone Invoice or standalone Credit Memo have a Subscription line field populated on all lines, then this is considered and processed as SuiteBilling scenario.
For this scenario, the purchase cost and its currency are sourced from the fields configured in the SuiteBilling Unit Buy Price and Currency in SMT Configuration.
The sell price is sourced from the SuiteBilling Unit Sell Price config option, the currency is sourced from the subscription. In case this option is not specified, the native NetSuite amount will be used, with currency sourced from the transaction.
SuiteBilling purchase cost are always in the final stage of SMT calculation.
