In order to be able to accept credit card payments via PayPal, you will need a "business account".
PayPal (currently) does not charge a fee if you upgrade your existing account.
For more information on how to set up a PayPal account and how to link it to ConfTool Pro, please visit this page:
Configure PayPal for ConfTool ProPlease note that some users/participants will also need a PayPal account to pay their fees:
Do conference participants need their own PayPal account? The PayPal business account itself is free, but PayPal charges transfer fees to the merchant (about 2.5% - 4.9%).
There are discounts available for nonprofit organizations.