Change service price for follow up sessions

My question:
How can I dinamically change the price of a service if the user has already booked the first session?

Product:
From the research I have done I believe this can be done with the wix Bookings API and the getMember function. But I am not sure how or where to start? And if this is even the ight approach. Any help will be highly appreciated. I also know this can be done with an automation that sends a cupon code to the user, but that just means more steps and I would like to automate it.

What I’m trying to achieve:
Let’s say Anna has booked her first one-to-one session, which is a service I already offer on my website. The next time she goes to book another one-to-one session the price of the service will be adjusted and maybe the confirmation buttons could show ‘Follow up’. I am uncertain about the details or the extent of what can or can’t be done; that’s why I am a little vage. I hope the general idea of what I am trying to achieve here is understood.

What I have already tried:
As I mentioned above, I could easily solve this with an automation, but that’s no precisely what my client needs. I have read the documentation and come up with the following flow (very simple, sorry):

  1. User clicks on follow up button
  2. If current member has a ‘FOLLOW UP’ tag:
    A. I will pass the hidden follow up service with a diferent price
    B. I will automatically add a discount or cupon code to the checkout
    C. I will modify the total at checkout for the specific checkout
  3. Otherwise the user will be sent to the normal first time service

Additional information:
I don’t want to create a booking flow from scratch. I rather use the one that’s already set up for all my services, but with that minor (or mayor?) modification. If possible.

Thanks in advance for the help!!

Codable: https://www.wix.com/velo/reference/spis/wix-bookings/bookings-custom-pricing/calculateprice

Hi Mukhia, Einat from the Bookings team here. This could be achieved by using bookings-custom-pricing, by using this SPI the user can tap into the pricing calculation, there use other APIs such as the members API and bookings APIs to determine what pricing to provide.
If you haven’t find it helpful enough, let me know and I’ll contact you with one of our developers.