ive been to chamonix twice this year! IMO its very good for beginers... even on the bigger slopes there are big wide greens runs... Dependant on where you stay it can either be very cheap or very expensive.
If you stay in a hostel type place (gite) its about £10 a night! otherwise you will be looking at one of the hotels or private challets and these arent cheap!
As regards to travelling we got a Bmi flight for £24 each (return ) from manshester to geneva and hited a car and drove to chamonix (bout 90 mins away from airport)
If you have never done it before then my advise would to be to get a few lessons before you go.. (5 will prob do) you can learn very quickly when there but you need a basic understanding of how to control a board!
Luckily the first time i went it was with a friend who was very good and i soon got better myself by watching him and taking my time on the wide green runs.
If you want anymore info feel free to pm me.. we are hopefully going again on jan 3rd next year
CheeRs
Phil