highway robbery
US /ˈhaɪ.weɪ ˈrɑː.bər.i/
UK /ˈhaɪ.weɪ ˈrɑː.bər.i/

1.
a situation in which someone is charged an unfairly high price for something
:
•
Paying $10 for a bottle of water at the concert was highway robbery.
•
The cost of that repair is highway robbery; I can get it done for half the price elsewhere.