I need help configuring the right widget add cost from each row.

Trying to create a spreadsheet like form to collect Ad payments from various advertisers/patrons from one Collector person.  I have 2 widgets that I've been playing with but can't seem to figure out how to summarize the cost across all rows.

I did check your form and it seems you have added "Configurable List" widget and input table field. Please note that it is not possible to add calculation for configurable list fields but same can be achieved in input table field. 

You may like to take a look at the following guide on how to perform calculation in input table field: https://www.jotform.com/help/343-How-to-Perform-Form-Calculation-in-the-Input-Table-Field

I would also suggest you to please explain your calculation requirement a bit more in detail. It seems you have added calculation values for input table dropdown fields but you have added a3 and so on. Please check the screenshot below:

Please explain your calculation formula in detail and we will try to help you.

We will wait for your response.

I was attempting to add the Cost column for all rows, but perhaps not understanding quite how to do it.  I want to show a summary of all cost that will then be paid via paypal widget.

You can do the calculations in the Input Table via conditions. In order to do this, you can follow this guide:

https://www.jotform.com/help/414-Calculate-Values-in-the-Input-Table-Through-Condition

Then you can add the Form Calculation widget on the form and calculate the total in it. Finally, you just need to pass the value of the Form Calculation widget to the PayPal integration. This guide will help you to pass the value:

https://www.jotform.com/help/275-How-to-Pass-a-Calculation-to-a-Payment-Field

Please give it a try and let us know if you need any further assistance.