All depends on the lights... but I've never heard of 275w halides. I've heard of 150's, 175's, 250's and 400's.
Not saying they aren't though.
But in retrospect I spend 300 bucks on one 250w ballast and pendant without the bulb.. It was icecap but still 300 bucks could have easily bought those 2 lights versus my one.
Depends what you want I guess