Is it possible to use a widget to generate a custom payment amount?

I want to create a dynamic form that generates a price for the customer.

Each time the customer would select an option, there would be another level of the form appearing or getting ''unlocked'' with only certain options appearing depending of his previous choice. The context is a registration form for a tennis academy. A customer would select in order : 1. Tennis program ---> 2. Venue ---> 3. Schedule ---> The price is automatically generated for the customer depending on the 3 previous options. Because each program is not offered at each venue, we don't want the customer to make an impossible selection, that's why it is important to block certain options of the next level.

To add a bit of complexity, each venue has a different pricing. Program A doesn't cost the same in venue B and venue C.

I haven't seen any widget  that could accomplish such action.

It seems to me that you want to automatically generate a scaled price for users based on their choices on your jotform. 

This isn't possible with widgets yet because we don't have one that fully supports this currently. So the only way to work around this is to use the donation option in the payment integration alongside the use of conditional logic.

Please see this guide here http://www.jotform.com/help/275-How-to-pass-a-calculation-to-a-payment-field for a better understanding of how to do this properly.