Question from Steph - Transiting for 15 hours

I have a layover in PEK for 15 hours and would like to go an see the Wall or go into the city during that time. If I get a transit Visa, do I still have to pay the $140? Can I get that it at the LA consulate? Also, I had a multiple entry one that expired on November 9, 2013... can I just get the old one renewed?