I'm looking for:

-stores in or near Chamonix that carry freeze dried/instant meals, the type you can be prepared by just pouring boiling water in the packaging.

-a good campingsite in or near Chamonix. Preferably cheap, quiet, ... I only require a toilet and a shower...

^^ that was me, I've having password/login issues

The largest store for gear etc is Snell Sport http://www.cham3s.com/

And for the camping, the cheapest is Les Arolles close to the bowling place http://www.chamonixcampinglesarolles.fr/UK/welcome.html

I prefer the Barrats http://www.campingbarrats.com They are very nice with electricity and wifi available.

If you have a car, the camping down in Les Bossons is really nice...and cheap.