Hi gburt ,
That field is calculated dynamically before being shown in the widget. ATUM Export Pro doesn't do that kind of calculation at this time.
If you want to get it directly from the exported file, you'll need to do some code customization. If you don't mind getting the total cost after the export, you can use the Spreadsheet software.
Apologies for any inconvenience caused.
Best Regards,
José Andrés