You're not terribly likely to get ripped off by a taxi from the official airport queue; just make sure they use the meter and you'll be fine. PVG to most places in Xuhui should be about 170, no more than 200. If late-night rates are in effect, allow slightly more.

If you have an early flight out of PVG the next morning, you might want to try for somewhere closer than Xuhui, but otherwise there's no reason not to just head in to the city after your arrival, whatever time that might be.