In reply to Osiris:
We thought it would be pricey so tried to take lots of food with us. Here are the few examples that I can think of:
Bottle of weissbeir - £2.70 if purchased individually.
Quarter of a lovely cherry tart which would feed 3 or 4 - £4.50
An ice cream in a cafe - £3.00
Two big sandwiches and two bottles of water on a terrace outside a cafe in Saas Fee - £20.00
One nights camping in a pleasant site for two adults, a car and a medium sized tent - £51.00 but includes free access to all the cable cars and chair lifts.
So, not exactly cheap but you are buying stuff from a Co-op in a remote valley in a tourist area. I have had more nasty surprises nipping into a Booths in the Lake District!
The huts were very expensive though. Particularly the Mischabel one, where there is no running water and was charging £6.50 for a 1.5 L bottle. I suppose though that huts are always expensive.
Hope this helps