OK, let us use real data of average manufacturing wages across provinces in China. For simplicity I will convert to US dollars and quote the wage per month as they were in 2011.
All figures are to be found on this site
We shall use the following 3 provinces to make a comparison:
1. Guangdong - Coastal province with population in excess of 100 million
2. Henan - Inland province with population near 100 million
3. Sichuan - Inland province with population of 80 million
Guandong has average salary at 440 dollars
Henan has an average salary at 507 dollars
Sichuan has an average salary at 225 dollars.
Yes, an inland province like Henan now has higher manufacturing wages than a coastal province like Guandong!
Inland Sichuan is still quite low but even at 225 dollars it is 3-4 times higher than in Bangladesh.
So already the big inland province of Henan cannot support the low-tech manufacturing as its manufacturing wages have risen to higher than coastal Guangdong, that has living standards as good as the poorer parts of the EU already
There are some other provinces similar to Sichuan that are quite low in manufacturing wage levels but their populations are less than 50 million and the wages are rising like a rocket. As an example the average manufacturing wage in Henan doubled between 2009 and 2011!
So I ask you, where are those 800 million impoverished Chinese that can do the low-cost jobs that cannot be done anymore in the coastal provinces?