Anyone have an estimate for what it would cost to get the head gasket replaced on a 2013 Range Rover Sport Supercharged?

Tech noted: "Bank 2 running rich and can smell coolant burning on start up. Applied pressure to cylinder #6 and saw bubbles coming from cylinder into coolant reservoir. Head gasket possibly blown or other internal cylinder head/engine damage".

It's not overheated while I've owned it, but that's only been 3 months. I had the coolant housing/thermostat replaced and had to add coolant a few more times, thought maybe they just hadn't filled it up all the way. Turns out, likely a bigger issue.