Is there an option to add "other" option to the products in the payment wizard?

On the donations page, we set up through paypal 3 different products.

1.  Membership is a set amount at $10 with options for quantity.

2.  Lion$hare has 3 set options but we want to add a 4th option as "other" where the donor can enter an amount not select a predetermined amount.

3.  Grad Gala has two set options, but we want to add a 3rd option as "other" where the donor can enter an amount not select a predetermined amount.

Unfortunately what you have mentioned would not be possible to do within the payment processing tool, but it would be possible by adding radio buttons to your jotform (just as you did) and then passing the value over to the payment processing tool.

What I would suggest is to check the following guides to see how to do that:

How to Assign Calculation Value

How to perform calculation in the form?

How to pass a calculation to a payment field

Of course and we are here if needed, so feel free to let us know :)