Those tanks look identical to a RG400 and a RG200. I don't know if they are but if the description and the photo are anything to go by then I wouldn't be suprised to find out they are one and the same (happy to be corrected).
http://www.fasttech.com/product/1536500-rg400-bottom-coil-glass-clearomizer-4-0ml
They cost about about a fiver from fasttech. So if they are the same product then that is a hell of a mark up.
The mini tank looks like a RG200
http://www.fasttech.com/products/1411/10006479/1528500
They cost about 4 quid.
I have a RG400 and a RG200 and I think they are cheap, the glass is not Pyrex and it chips very easily when screwing it back together and the tank is not a high grade steel or even medium grade. There is no comparison with Kanger stuff or Anyvape.