With S$500k profit, you can target 4-room HDB resale flats in Punggol priced from S$538,000 to S$835,000, or 3-room units from S$480,000 to S$638,000. Options include Punggol Drive (~S$670k), Northshore Drive (~S$751k), and Punggol Walk (~S$650k+), near MRT stations, hawker centres, and parks.