Order form: With dynamic fields

I need to create an order form that users that will present users with blanks for a part number, description, qty, cost that will then figure total cost and allow them to add more lines if possible with a grand total displayed. I've found widgets that are very close, any suggestions?

Well one way is to use a payment integration. 

Setting-Up-Your-First-Order-Form

Then the other way is to use standard fields to create your own cart. And use a form calculation widget to calculate your total. Then you pass that total to a payment integration. 

Instructions here:

How-to-Pass-a-Calculation-to-a-Payment-Field

Unfortunately the dynamic widgets which allow you to add a new line (one per product) wont allow you to add up the prices of your orders. If you like we can submit a feature request?