Light Question

Ok guys I currently have my Widow growing under one 400 HPS. I used the same light for growing and flowering. Now that I have a little more money I want to upgrade my lights and become a professional and use the 400 for the grow cycle and buy a 1000 HPS for FLowering. I wanted to know your opinions on how much of a difference I will see. Is there a big difference in the elctrict bill? Any thoughts please

oh yea...How much should i plan on spending on a 1000 watt hps

I bought the sun system 7 super spectrum it has a 400w mh and i got the one that has the 600w hps they are both in one reflector both run off one ballast i use both lights whole way through with air adapter lens everything i spent $525 Love the light not bad on electric $5/ month