Do I need to apply for the tourist visa from Philippines or might it be cheaper and easier to show up at the airport and be dealt with my violation there? How great might the fine be in my case?

I am travelling from Philippines to Russia through Shanghai and Urumqi. All together I will spent in China about 80 hours, which only 8 hours exceeds the 72 hours free transit regulations). However I am arriving to Shanghai and departing from Urumqi. Thnx.