New Grow Room

I'm starting a new grow room and are a little worried about electric costs.. How much does it cost to run a 400w sonti-agro.. I know its going to differ from country to country.. I'm in the U.K.

Any help in keeping running costs down would help.

Thankskiss-ass

How dya think i feel im lookin to use 2 x 600w HPS loooooool, can anyone ansa my Q while ur at it?