250w hps in 600w ballast

Hi guys quick question here. Found a guy who will sell a complete 600w kit very cheap. Was just wondering if it would be safe to put a 250w bulb in it as electric bills need to be low and there are heat issues. Also if i can do this would it still be using 600w of electricity? Thanks!

I think it depends on the type of ballast. Any specifics?

dont try it

ummm.... no

not sure pall think its old tho lol think im just gonna get the full 250w kit although its such a shame this 600w kit is goin for £20 thats about $30-$40 I think