Cost to acquire Chinese users 2013
As reported by Distmo's February 2013 issue, for China, the average cost per install of an IOS user is US$0.90 while the average revenue per install is US$1.13. The average profit margin per install is only US$0.23, around 20% of the average revenue per install.
This data is probably not relevant for Android but it is noteworthy as an reference until more detailed Android based data is available.
As reported by appflood, in China Android app stores, it is possible to "pay just $0.30 per install for Chinese users, as we’ve seen on AppFlood. Compare that to the minimum $1.10 bid for a user from the U.S." This rate is consistent with the rate reported by wandoujia, at US$0.25 per install for games and US$0.18 for apps.
If you look at the advertising agency's prospective, as published by appflood for Android, the cost (eCPM - effective cost per thousand impressions) seems to be much lower - "it’s comparatively cheap to buy local users at $0.35 eCPM (Q3 2013)."