Sumif Problem
 

Hello,
I have an issue using sumif. I am trying to sum a column if the work
area equals a certain value, but I only want it to sum values that are
not duplicates.

For example,
A B C D
E
Work Area Part Price of Part Qty of Parts on hand
total cost of inventory

Multiple work areas use the same part, which is why I am selecting the
value for the work area. I am summing column E. But a work area could
have ordered the same part multiple times, and I do not want to sum up
duplicate values from column E for the same part.
If anyone could help me with an array function, I would greatly
appreciate it.