In reply to TheFatClimber:
If cheapness is what you're after and you're planning on driving then I'g go via Belgium, Luxembourg, back into France, Switzerland (entering at Basel) and on to Chamonix via the Col de la Forclaz from Martigny in the Rhone Valley.
It only takes about 3 hours longer than driving down through France but will save you about £150 in autoroute tolls on the return trip, its all free except one short stretch on the A4 between Metz and Strasbourg.
Also fill up your car in Luxembourg with the cheapest fuel in Western Europe but don't waste time coming off the motorway to avoid service station prices as by law its the same price everywhere in Luxembourg.
Post edited at 20:55