I don’t know if this answers your question, but my UCB student did an independent study program applying to London School of Economics directly, although later we learned she could have taken the same class through UCB. She did a University of Geneva class her second year through UCB.
My youngest just finished freshman year and is studying at Harvard Beijing Academy this summer. Reportedly the two best language abroad summer classes are Harvard and Princeton.
The costs of airline flights was totally outside the cost of the program/class. The program costs were a few thousand dollars, not $1000. I have heard about students who get scholarships to study abroad, but my students were not as lucky.