There are currently 2 Pages which links to the Paypal
1. Go to Page Builder under Appearance and select Home template.
The first button that you need to change is found in "Introduction" block, you can expand it by clicking on the arrow opposite the name of the block. Look for "3. Button Settings" there should be an area that says "link". That is where you will enter your desired URL.
For the second block where you will put your paypal link, scroll down and see the block that says Purchase, click the down arrow to expand it. Look where it says Link and change the # with your PayPal link.
After editing these blocks, make sure to click on "Save Template" on the upper or lower right hand corner to save your updates.
2. Next go to Portfolio template, go to each snapshot and change the PayPal link from all the features.