Changing LOOKUP table prices changes previous sales too!

This is what I had in mind

=IF(C2="",0,INDEX(ProductLookup!$B$3:$G$11,MATCH(C2,ProductLookup!$A$3:$A$11),MATCH(B2,ProductLookup!$B$1:$G$1)))

The First MATCH uses the SKU to find the proper row in the ProductLookup
The Second MATCH looks to see at the DATE and matches the proper column in the ProductLookup. Therefore if there has been a price increase before the ship date, the new price is reflected.

I am sending you your file back with the equations


I hope I explained it well enough