(1)The COOP (2 blocks from Zurich Hbf), has lots of hot dishes, and they have a microwave also, so you can make items "freshly" prepared.
(2)Watch for daily (weekly) specials at Migros and COOP--to cut costs even more.
(3)The Migros at the airport (generally, startling in the early evening), sells some sandwiches at a discount.
(4)In some of the smaller cities in Switz. you can get the local beer for as little as 0.65 SF for 1/2 L at the COOP.
(5)Migros does NOT sell wine or beer, but the COOP does and you can find some reasonably priced wines.