I'm guessing that both of these endpoints are pushing up prices because a lot of airlines don't bother filing fares that include them. Nevertheless, it's worth trying a variety of combinations (e.g. CVG-JFK might not be a cost prohibitive add on to JFK-PVG). In my recent searches, I've found that NYC, BOS, and WAS are the best east coast gateways and both SHA and HK are good on the China side.