Switzerland can be a pricey place to stay.
If you want to spend a few days in Switzerland while visiting France, you can at least save on travel costs by taking the train on TGV Lyria network.
Fares are as low as 25 Euros one way are advertised if you book way in advance.
Best fares available in August for mid-week trip from Paris to Geneva, would be for departure on August 28 and return on August 30 at 48 Euros each way.
Want a long week-end (same price as above each way), leave Paris at 6:11 pm or 7:11 pm on Thursday, August 30 and return Monday, September 3 at 6:12 AM.
Trip from Paris Gare de Lyon to Geneva Cornavin takes slightly over 3 hours, city center to city center, less time than it would take you to go to the airport, go through security, check in and fly.
For extra convenience, you can download schedules from Paris to Geneva, Bern, Neuchatel, Lausanne, Zurich, Basel to your mobile device via Lyria Mobile...
Information on both mobile and regular site for TGV Lyria are available in 3 languages, English, French and German.
Add 45 minutes to an hour and a half travel time and a few Euros more each way for trips to Lausanne, Zurich and Bern.
(* Schedule and Network Map images from TGV Lyria website)