Field help (TRFPRI)

This field can only be accessed when the source is a Purchase order.
It is used to specify if a price transfer must be performed from the purchase order to the sales order.

Yes

Prices, discounts, expenses (etc.)  are initialized on each sales order line based on the price and discount information entered on the purchase orders. If the calculated sales price is null because the purchase price is null, the price list search will be applied to determine the sales prince.

No

No price transfer is performed. The price list search is applied in order to determine the sales price.

 This setup only concerns standard sales orders and not open orders.