Taxi: From Longyang stn to PVG airport 110RMB
Train: 40RMB one way with airticket, or 80RMB round trip
Traffic in shanghai sometimes is extremely terrible. Try not to take taxi. Subway is a lot faster, and all starwood properties in shanghai are quite close to a subway station, especially royal meridien shanghai, sheraton pudong, and four points pudong. Taxi fare in shanghai is not expensive, but trust me, traffic jam is really horrible.