food is expensive in $witzerland, but you can stop somewhere outside of the country and stock up, we stopped in France and filled the van. Camping is 5chf or 4euros per person, there are lots of no wild camping signs and possible fines mentioned.
personally thought Magic was good when i went in summer, but i think next time i go back to Swiss I'll wait for the cooler temps and go Chronico and Cresciano which i think are nicer.