Disembark Tour from Cruise Ship

We are arriving in Shanghai on March 25 at 7:00 a.m. at the conclusion of our Princess Cruise. We are taking a disembark tour of the city after we get off the ship that lasts until 2:30 p.m., at which time they take us directly to the airport (PVG) for our flight from Shanghai to Los Angeles. It sounds like we do not need to get the entry permit because we are flying directly out of Shanghai to the States after spending 12 hours there, but for some reason, Princess Cruises is recommending that we get a single entry visa. This is very expensive for me and my husband, and sounds like a waste of money for our situation. Any advice would be appreciated!! Thanks!