Booking form and payment

Hi

We have created a booking form but need to add some dynamic data.

Our services have different costs associated. Is there a way for a form to calculate the time between submission of a form and a booking time and date specified within the form to then show the associated cost of the service?

Further, once the form is submitted i'd like the user to be directed to a payments page where the cost of the booking is shown and the user can complete the payment process. I have been looking at a few options such as stripe, but unsure how to progress.

Thanks

Robbie

and depending on the time till booking