Do it if you can man, sometimes it is less expensive than living in the US. You may never have another chance outside of school to do something like it. I was also a screw up in high school, and got really lucky getting into OU. I didn't understand life can be serious business when I was in high school, and did tons of stuff I probably shouldn't have, killed a lot of brain cells, and never went to class. It was a good time though, and is part of what made me who I am today.

I came to Germany first in 2005/2006 with an exchange program, I met my girlfriend (future wife, but don't tell her yet ;P), and ended up coming back. I now study medicine at one of the best medical universities in the world for 104 Euros per semester!! My parents, hard work, and a bit of luck (or whatever), came together to make my current situation possible, but none of it would have ever happened had I decided to stay in Oklahoma. Now I am saving a ton of money by not going to med school in the US, and have a mini mountain to ride on as my backyard =)