I am from China, although I am an American now, I do run businesses and some of them are in China
When I read the " ... for a maximum of £200 to £300 a month" I know that TFA is a big bullshit !
Really? I think you don't know China, nor do you do any business there. Zhejiang has the highest minimum wage, and it peaks in Ningbo at 1550 RMB per month (this information is out of date a bit, but pretty close to current conditions). That's 160 pounds sterling. Given that only inexperienced/brand new workers will earn minimum wage, the range of 200 to 300 pounds sterling is completely understandable and expected (that's about 2000 to 3000 RMB per month).
Additionally, new sales staff/office trainees in places like Shanghai run about 3500 RMB per month (low-level white collar) and a fresh acoustical engineering grad from the University of Nanjing (top Chinese school) in the top 10% of his class earns 4500 RMB (about 450 pounds sterling) per month. A very experienced (8 year) office manager with excellent English skills and 5 years experience working for Western companies earns 8000 RMB per month. How do I know? I just returned 4 days ago from Shanghai, where I signed contracts for all those positions.
Factory workers in China in the East rarely start at more than minimum wage. 1500 to 2000 RMB is a very good starting wage, and line bosses/leads may earn double that amount. Well below your 5000 RMB per month minimum salary.