Booking calendar + shoppingcart: Consulting ??
You can submit a request here https://www.interactivetools.com/support/request/ with your project details and someone will get back to you. I don't believe I have personally seen any type of Booking calendar plugin existing yet.
If it proves to be beyond your budget to create this functionality from scratch, you might want to look at some of the scripts from http://phpjabbers.com
Hope that helps.
Take advantage of a free 3 month trial subscription, only for CMSB users, at: http://www.thecmsbcookbook.com/trial.php
- Booking system and room occupancy for a couple of backpacker hostels (no payments) ,
- Event Booking system with Simple Cart payments,
- Complete fractional/shared ownership resort management system with member date allocations, time-swapping etc no payments.
Greg@Itools has done the majority of those with me