TGV Germany has a late comer offer from EUR30 one way.
The
TGV CH site gives good deals to Paris as does Deutsche Bahn and SBB. This offer can be used to go cheaply to say Nantes, Rennes or Bordeaux all in FR.
TGV DE URL
Best TGV fare basis are the
Piccolissimo or
Piccolo ( all restricted / Zugbindung ).