Generally, brands like Wenhe, Cezanne and Baifuchuan have professional clothes, and the prices are acceptable. But in fact, you don't have to wear professional clothes when interviewing. Just choose clothes that are generous and formal and suitable for you, because I guess you must be a fresh graduate. In your present situation, it would be good if you can show your vitality properly in the interview. Too formal a suit will not pass easily, but it will look old-fashioned, thus affecting the interviewer's first impression of you.