Entry requirements for USA citizen into China on a tourist visa?

My questions? {1} I'm planning on traveling over land into and out of China by bus, VietNam. What are the requirerments to apply for a tourist visa? { no plane ticket or hotel reservations} I will not be flying so no airplane ticket. I am also in Thailand now and not the USA. {2} Tourist visa is 140 dollars today, October 4th, 2013. I was under the impression the visa was 300 dolllars for an American citizen? Thanks for any help or advice.