Any idea where they transfer the Taobao Street in Tianjin?

The street is closed, not moved. For market like that, you can go to Dahutong Market. It is at South Nanyunhe Road, Hongqiao District.

Any other markets or streets like that where we can get cheaper stuff?

Yanghuo Pedestrian Street near the Tanggu Subway Station is also a good choice.

The street has been moved to huanghe avenue. It now inside a 3 story mall called xin taobao jie, they sell all from sporting good- office articles all very cheap and on the 3rd floor they have super cheap clothes laying in piles . Talking 5 yuan per piece. It is not quite the same as the old taobao but still very good. bus Nr 3 drops you off 200 meters from there. But the place is quite hidden so ask around

The bus stop is called yan an Lou 延安楼 or you can the take the metro xian yang lu 咸阳路 the mall is in This place 新南马路五金城。