We reach Shanghai on May 3 at 5am & flight to SF at 10pm. Can stay at airport & go city tour. Price?

So u are Singapore passport holder? Well, you are qualified for the 24h visa-free policy, so you will be allowed to get out of the airport for the city tour. I suggest you put forward your request for transit to your airline in advance, so that the airline can declare this to the Immigration Inspection prior to your visit. You will be granted a transit permit upon landing, with which you can get out of the airport.

If you are referring to the price for city tour, it is hard to say! Actually, you can enjoy a tour by yourself at the Bund, Nanjing Road, Xin Tian Di and other attractions. If you join a day tour, it may charge 40-50USD per person.