Remove contents from a cell if duplicates exist in a different column

Basically I'm trying to show the balance of the invoice only once without affecting any other data on the spreadsheet (assuming there's duplicate balances and I can't just remove duplicates).
For example, in the attached document, I would want to have only the balance that's reflected in E4 to show and cells E5 through E7 would be blank. Again, this should not effect any other columns on the spreadsheet but an additional column can be added if necessary.

Hope that makes sense.

Thanks!!

Perhaps I should elaborate...
The end goal is to create a pivot table where the invoice numbers are displayed as the rows, the count of the individual line items and various details will display as the columns, and the balance will be displayed as the amount outstanding for the invoice. However, for that to work properly, I would need multiple invoice numbers (keeping the individual line items) with only one balance for the invoice.
LOL this stuff is way harder to write out! Let me know if you think you can help but need additional information...

Thanks so much that solved it!!!