Originally Posted by
blueyama
This then affects the visa situation as the free 72 hour transit visa is valid for the first unannounced stopover (e.g. Beijing), but crucially not the second stopover (which in my example would be Shanghai). I have read that people have had to pay for a tourist visa in the second transit airport and it's making me worried!
As
moondog suggests, check your flights via google.
However just on a technicality regarding 72-hour visa... if you have more than one stop in China you will not be eligible for the 72 hour TWOV - 24 hour TWOV is all you'll get.
You will either (a) be refused boarding at your point of origin or (b) refused entry into China on arrival or (c) forced to change or buy a ticket to make your travel plans compliant.
There is no option to 'buy' a tourist visa at any point in China.