Hi Alex
Migros offers french lessons for all levels, and their price is the cheapest I can find in Lausanne(among all the languages schools). I would suggest you starting with the intensive course (10 hrs a week, every morning from 9:00 to 11:50) since you are a beginner, you can catch up faster this way.
http://www.ecole-club.ch/framedef_1....240CA571086C03
Two months course will cost you around 1,5k.
If you have limited budget, try the lessons offered by the university. Six weeks sessions for beginners, chf 1,1k, everyday 8h45 to12h00 .
http://www.unil.ch/cvac/page5646.html
If this is still too expensive, but you are living in Lausanne (not Renens, Pully, etc those little towns around lausanne), go to the Bureau de Etranger and ask for a brochure where you can find infomations about the
FREE french lessons offered by the goverment, but you need to pay chf 10 or 20 registration fees. Those lessons are held once a week.
For the French-English exchange, humm, i dont think it works well, everybody speaks some english these days. I know French-German exchange is more popular. But of course you can give a try in the university.
Ella