I think the prices have to reflect the cost of fruit, the overhead costs of staff, fruit preparation, rent for the store space etc, so ... are they the sort of price I'm willing to pay? No. But are they too expensive for all the costs that need to be covered ..... arguably not.
Yeah, I think Meg's probably right about the cost. They're exxy compared with soft drinks or tea and coffee but they probably have to be. It's a lot more economical to make it yourself at home, but you pay more for the convenience.