First question I would ask is how old are the ballast? They don't last for ever and the older they get the less efficient they get and the less they produce. I have two of CV's 250 watt double ended fixtures with there ballast and they are OK. I also have two of CV's 175 watt electronic ballast and love the heck out of them. 85$ for a 400 watt electronic ballast (Not Pulse Start)with a two or three year warranty sounds pretty good to me.