Batteries from Taobao.com, ultra-capacitors

I'm new to forum, just learning how to build EV - it is cheaper for me, because I'm living in China.

searching for batteries in Taobao.com, chinese ebay

What I found:

12v, 200Ah, 1088rmb (173$), other places similar power selling for 788RMB

http://item.taobao.com/item.htm?id=...li_trackid=1_bfec1d6dc6370d30e756e612ca809465

Lithium, 12b 50Ah, 2650rmb, (424$), weight 10kg

http://item.taobao.com/item.htm?id=..._2956818_10060724,0:1340433948_3k1_1783564695

Chinese now using ultra-capacitors batteries, less expensive and more rechargeable, up to 100 000 times

http://english.chinabuses.com/news/2012/0614/article_5505.html

I'm also searching for ultra-capacitors to build own batteries, it may be much less expensive

2.5v, 630F, 13RMB
http://item.taobao.com/item.htm?id=9897449079&_u=nl7jn38e865
2,5v, 2000F, 60RMB
http://item.taobao.com/item.htm?id=16543352275&_u=nl7jn38be21

http://www.alibaba.com/product-gs/515816854/super_high_capacitor.html
10000 F, 4 Ohms
2.7V3000F0.45 Oh, 63×140screw
any feedback will be greatly appreciated

Jan