If you are looking for pipes then Yanghuo has many of them, you can also buy really old pipes and with cool designs on them. They have both big and small ones, I paid 5rmb for the small one and the big one i wanted was 80rmb after 20 minutes of bargaining. You can find the pipes in some of the shops on west street and around and as well on the sidewalks you will see people with them on a blanket or something.