y790 really isn't so bad. Or, if you don't mind flying to TSN, MU 5189 (110p) and 5563 (650p) are only 310 (70% discount) on ctrip.

I started a thread about the BJ - TSN trek a few months ago, and there has been one more since. Basically, it will add an hour+ to your trip and is kind of annoying. But, if you have time to spare, it might warrant the $70 savings.

Side note. Whenever SHA-PEK is expensive, in addition to looking for SHA-TSN, I like to research HGH/NKG-PEK and Wuxi-NAY. While I wouldn't go all the way to Hangzhou or Nanjing just to save $50, I often have business contacts in such places, which helps tip the scales.