How do I vary payment collected based on submissions

I am taking orders for senior banners for a high school.  I have created the form to add the fields required and payment for one banner.  I'd like to be able to have someone order multiple banners on one order.  The way I have it set up right now is for them to complete an order and then be redirected to a blank order form if they answer the 2nd option of completing another order.  They will have to go through the payment/credit card process again though.  How would I be able to have them add multiple banners to one order.  I'm thinking I could make a condition to add the fields again to the page if they chose an option to by another and I could add "choose a quantity" to the product upon payment but not sure how I could guarantee that the quantity they chose matched the # of submissions.  

Thanks for you help!

Thank you for contacting us.

You may consider adding the quantity to the payment tool.

And also the student fields.

Then, setup the show field conditions based on the selected quantity.

Example:

https://form.jotform.com/73447415900960

If you need any further assistance, please let us know.