I'd check to make sure the DLU return point isn't jacking up the total fare by seeing if swapping in Kunming or Chengdu changes it. Basically, CA can charge a premium if you set Beijing as the destination because it flies nonstop (unique product). It can also charge a premium for small markets like Dali because there isn't a great deal of supply. Large second tier cities, by contrast, are often much more competitive (e.g. ~7 airlines can get you from LAX to CTU with a single connection).

YariGuy I'm guessing that TFU (instead of CTU) is CA's default filing from LAX, but I'd also push for CTU, all things being equal.