Take paypal payments equal to field value in views

Bit of an ask, but i'm wondering if and how it would be possible for me to take payments on my drupal site. I'm going to have views which display a list of charges and i can then manually add payments i have taken for them.

So the view has two sections one with a list of charges, the second with a list of payments. Both lists are populated by nodes which are children of the of the page itself. Then a field (either computed or views calc-ed) will show the remaining balance outstanding.
e.g.

Charges [a]
labour - £30
materials - £35
fees - £20

Payments received [b]
Cash - £40

Remaining balance (calculated [a] minus [b])
£45

Then i want a button which the visitor can click that takes them to paypal to pay the remaining balance. Whatever it is.
What's the best way to go?

Thank you guys in advance, you're always helpful.