Save on groceries - FairPrice, Giant, Sheng Siong, ColdStorage, Redmart, Prime Supermarket, Guardian, Watsons and more - diffmarts Singapore. diffmarts search, monitor and compare groceries from all Singapore''s major stores. Find out the cheapest price from among FairPrice, Giant, Sheng Siong, ColdStorage, Redmart, Prime Supermarket, Guardian, Watsons