SFO-PEK/PVG
If you get a Chinese visa ($140 for 10 years), you can get 25K PQM with two weekend trips and they will cost less than $1000.
Edit: For inbound, you can route thru NRT to avoid Chinese visa (use TWOV). The total cost for two SFO-PEK trips is about $1100.
Last edited by Kmxu; Aug 15, 2018 at 7:45 pm
Reason: Routing through NRT to avoid visa