Then I would suggest Create 2 Costing Keys
a) ABC - Costing Key which reads Cost Matching Goods Issue Date
b) XYZ - Costing Key which reads "Current Std Cost Estimate"
Assign Costing Key ABC as 1st Costing Key and XYZ as 2nd Costing Key
That ways, you will always read the Cost Matching Goods Issue date as first choice and the other once as fallback option
Ajay M