There are currently $466 roundtrips available from San Jose, CA, to Shanghai, China, according to The Flight Deal. The deal is on Air Canada and includes all taxes.
The fare is valid for travel from November through early December 2017, and January through April 2018, for departures and returns from Monday through Thursday. Be sure to book your flight at least three days before departure.
You can use ITA Software Matrix Airfare Search to search for availability. According to TFD, using the following search criteria works best:
Then, you can use TFD's Priceline link to actually book your tickets. (Using the dates from the search above on Priceline knocks down the price from $489 to $466.)
Book soon, because this fare could be gone within a couple of days!