Now CX has a sales from some Chinese cities, apart from PEK/PVG to SFO at Approx USD $1,700. All in I class fare, CX/KA only. it also seems no min/max stays required.
Examples:
1.
TAO-SFO at US$1,696 (CX/KA only) widely available
2.
CGO-SFO at US$1,774 (CX/KA only) widely available
I believe there must be more cities in China that KA/CX flies to have the same sales, but I did not check all.