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.
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