Actually to maintain a western standard of living your costs will probably be more in china, since many western brand name products are imported (despite being made in china). For example an apartment in shanghai can cost more than one in NYC, iPhone costs more, etc.
Agreed with the cost of living. No matter where you go in the world, if you want to live an American lifestyle - car, big house/apartment, western products - you will pay just about the same as living in the US. However, if you can live like a local, your cost of living will drop dramatically.
Even my relatives stopped buying street food for me there. Generally it's really unsanitary. Even street food in NYC is unsanitary, china is definitely worse.
Whatever you do, avoid street food.