Dec 11, 2010 - 3:03 AM
Depending on your other plans, you can cheap tickets on http://www.tgv-europe.ch/fr/ and www.sncf.fr websites. I have personally seen Paris to Basel for 20 and 30 EUR !
But you must reserve in advance.
Try looking on low cost airline websites, particularly to Basel airport
There are discounted overnight coach services from Porte de Bagnolet too to Basel and Zurich