If you need reasonable solution to Shanghai you may fly with classic European airlines Lufthansa or experience service of 5-star Hainan Airlines. (ranked by Skytrax). Return flights from Benelux to Shanghai are now available from €395 (Amsterdam, Lufthansa) or €418 (Brussels, Hainan Airlines). This is for round trip flight including all taxes and checked luggage.
Lufthansa is running their promotion for flighs returning back from China latest on 30th of June 2016 then from September till beginning of December 2016. To check available dates you may search directly at their website.
To book your flight from Brussels with 5* Hainan Airlines please look for travel dates till 17th of June or from 16th of October till 15th of December 2016. Based on date of your outbound flight to China.
Booking sample of cheap flights from Benelux to China (Shanghai) from €395.. In this case you would depart from Amsterdam to Shanghai on 27th of May 2016. Your return flight from China back to The Netherlands would be two weeks later, on 11th of June 2016.