China's domestic airfares are highly regulated and are correlated with each segment's distance--a round trip simply costs double and you pay for A to B plus B to C if you have to connect.

With Y (or "Y100") fares regulated, then there are the various discount levels in the multiples of 5% or 10%. My recent 30% discount segment on CZ was displayed as "Y70" on the ticket and "G" on international systems. Anything less expensive would earn me no miles on NW.

Every discount level provides different refundability and rules etc. On Ctrip's Chinese display, Y70 is listed as "7折" and Y45 as "45折". (Chinese count how much you pay, not how large the discount is.) The English listing is more simple, but more friendly to booking from abroad. In addition to the discounted fares are fuel surcharge and airport tax.

If you have Skyteam elite status, you can still reap benefits--even if you buy non-earning discount classes--such as priority check in and seat assignment.