May i know where is the best place in Beijing to shop tailormade suits with bargin price?

You are suggested to go to Yansha Outlets Shopping Center. There are several stores that sell such suits. As I know, the prices are acceptable. It's located at No.9, South East 4th Road.
From Wangfujing Street, you can take a taxi directly. The cab fare is about CNY 35 in the day time.
For halal foods, you can go to Muslim Mansion. It's located at No.241, Wangfujing Avenue. You can find authentic halal foods there. Hope you like.