When I went as a college exchange student in 1988, it was a true exchange. I paid to go to school and then went in a different country, while the student from the abroad school took my spot at my college. My tuition in my US school covered the program completely. It doesn't sound like this is an exchange, it sounds like a trip abroad to study. Not the same at all. I would look into the abroad programs that the college your child is expecting to go to already has in place. If it is an exchange, then that's how it works.
Both have value, and study abroad is wonderful. But the money thing is b
best addressed by the exchange, it would seem.
ADD: The college I went to in the states was more expensive than the sister college in England, so the cost was completely covered.