You don't need a trasit visa as long as 48 hours. Well, if you will stay at the airport for 12 hours, it is not reasonable to stay at hourly hotel. Please book an airport hotel, which costs around 300~400rmb. When will you come to Shanghai? it is worthy to know that the hotel rate is high during the expo to the end of Oct.

Thank you for your reply, Mr. Leostar. We will not be in Shanghai until January, so the Expo will not be a problem. I am still curious to know the rate at the hourly hotel. I assume from your reply that showing your passport and an outgoing ticket is enough to leave the airport. I am worried about making a booking for a hotel and then being told I need to purchase a visa or that I am not allowed to leave the airport. Again, thank you so much for your attention to my letter.