The obvious difference between the China and the UK is that China's PPP GDP measure is always considerably greater than its US$ measure whilst the two measures are much closer for the UK.
This means that a US dollar exchanged for Yuan and spent in China will buy considerably more than an actual dollar would buy in the US. The closeness of the UK measures means that a pound Sterling exchanged for Chinese Yuan would also buy a lot more in China than a pound would buy in the UK. In this sense it is cheaper to live in China than the UK.
