Two grand for 1 room 2 nights

I'd be kipping in the train station mate as no way I'd give in to that extortion. Unfortunately though there is plenty that would and that's why they know they can charge what they want and get it as well. They have you over a barrel mate
If they have taken a deposit off your nephew mate at that price I am pretty sure they can't ramp it up down the line. It's a binding contract once they take that deposit. Just don't agree to any change of terms and tell them you will see them in the small claims court over it. You will 100% have a case and you will win.