Would i be better off going to 400 watt HPS?

Im currently have 4 plant, all around 3 feet tall, execpt my purlple one, which is reaching 2 feet. They are currently under four 48'' plant florestent bulbs, 2 per ballast, each bulb running each at 40 watts. I have two 24'' plant florestent bulbs on one ballast, running at 20 watts each. I also have a compact florestent work light and at grow incandesent light which is 65 watts. What would be cheaper energy wise, taing all the light i have in there now or moving to a 400 watt HPS?

4 plants under 400w hps, yes, go for it! will be beaut.