SAP takes the price either from info record conditions or from last PO.
the price field in : Purch Org data 1 of your info record is just an information field for the user.
this field is not taken into account for price determination.
when you create the info record manually and enter a price in that field, then SAP creates automatically a condition record based on that entry. once the condition is in place, this field gets protected.
It would be a massive modification if you want to use this field instead of conditions or last PO for your pricing