That will depend on the way the leg is broken and the damage it caused. If they can just pull things right, and give some supports it may be relatively cheap (which is still over $1000 at least). If it's all complex and even requiring surgery, then adding one or two zeros to that amount I just mentioned can go pretty fast. Not sure if you have that in cash, but I don't. And when it comes to heart problems or diseases like cancer, the amounts you'll have to pay when you are not insuranced are beyond your budget unless you are a millionaire.
I've seen a recording of a woman who was not insuranced who came back from treatment after a heart seizure. When she received the bill she was about to have another one. I never heard somebody say "oh my god!" so much in less than a minute. Not even in the video where somebody said it many times (in Italian) when they captured to collapse of the bridge in Genoa on film.
Of course, when you realize what goes on during surgery, you can understand why it's so expensive. Not only do the doctors get paid much due to having a huge responsibility (you literally bet your life on it they do their jobs well), but if you know how much work is required before the operation room is ready to welcome the patient. Let alone the costs of the tools the doctors must have at their disposal, and the stuff they need to keep the patient asleep during the entire operation...And that is not even the tip of the iceberg...
Cut short, Obama-care was to prevent people from financial problems because they required medical treatment. It may go against the idea of "freedom" that the U.S. stands for, but maybe the knowledge that whenever you're life is on the line due to medical problems you at least don't have to worry about a bill you can't possibly hope to pay, grants more freedom.
Or maybe that's just a matter of perspective :P