If you do not have insurance in England, the prices are actually higher then what they are back in the states. Ask any visiting foreigner that needed treatment. Heard a story from a business associate. Prices were extremely high. Might have been due to that pound exchange rate back then, however. Was about 1.5 to 1.
Don’t really have a problem with foreigners having to pay for treatment. They haven’t spent their lives paying into the system.