400watt hps

Would this be ok to grow 5 big bud plants under??
i'm going to buy a lamp today and am contemplating one of these as a 600 mite be hard on my electricity bill??? plz opinions

600 watt lumatek ballast. More lumens less electricity as the ballast is digital. 400 watt is good for a small space but from experience is not really enough to get a good yield from 5 plants. Yield was about .25 - .35 grams per watt with the 400 watt light. So if 3 - 5 ounces a grow is enough go with the 400 watt. More light more yield. IMO