I want to start introducing more fresh fruits to my families diet. Where can I buy more "angmoh" fruits at reasonable prices - fresh cherries, blue berries etc

Supermarkets in heartland areas usually sell those berries at a cheaper price compared to Cold Storage, NTUC Finest. Try supermarkets like Sheng Siong, Shop n Save or Prime. Alternatively, you can get berries at cheaper prices from those traditional fruit stalls in wet markets. There is one in Bukit Gombak -- my mom usually gets fruits from the stall there and it's relatively cheaper.