3 hours appointment = 3 times to book

Hey there,
I have set Time Base Duration for 60 min.
But most of the customers wants to buy more than one hour each time (because it is a ski instructors marketplace), sometimes they buy 3 or more hours so they have to go to book 3 times for a 3 hours appointment.
Any idea to do that in a easier way?
Also, I would love to set something like coupons for 3 hours discounts...

Thanks for your time.
Kind Regards,