What is the cheapest transportation from PEK T2 to forbidden city hotel atNanheyan st. Doncheng?

The cheapest way for you is to take the airport shuttle bus line 3 from the airport to Chaoyangmen and then catch a taxi to the hotel. The cost for the shuttle bus is CNY16 and the taxi fare is about CNY10.
From the hotel to Mutianyu Great Wall, you can firstly walk to Wangfujing to take subway line 1 and transfer to subway line 2 at Jianguo Lu. Get off the subway at Dongzhimen, then take Tour Bus No.936 at Dongzhimen Outer to Mutianyu Great Wall. The bus ticket of a single trip costs CNY 16. The Admission Fee for the Great Wall is CNY 40 .