I can think of one report, Ron. 

We can pull up the Transaction List by Customer report and customize it to show invoices only. It will show you the total amount of each transaction. Let me guide you:

1. Click Reports.
2. Go to Customers & receivables.
3. Select Transaction List by Customer.
4. Click Customize report.
5. Go to the Filter tab.
6. In the Search Filters field, select Transaction Type.
7. Under Transaction Type, select Invoice.
8. Click OK. 

You can memorize the report so you'll no longer go over to the same customization process.

Let us know if there's anything else that you need. We're just one post away. Take care!