but I am thinking that I could walk from Beijing to Yunnan and get a boat to Thailand to save money.

You cannot be serious man, it's a long long way. Even when you get to Yunnan you will have to keep heading south to get to Xishuangbana in order to get a boat to Thailand. You must be pretty gutsy, man. If I were in China at the time you start walking, I'd meet you half way and buy you beer and food to show my respect. Can you give us all regular updates on your long journey? You will need to live on rice and noodles to save money though, otherwise you may as well get on the train. A hard seat would probably work out cheaper. May God be with you and good luck. By the way Yuming is not that bad a gig if you have the right attitude, go and try them first. Muhammad.