I understand where you are comming from on costs.

After reading alot I determind that it was worth going with HID lighting. pros: Very large increase in lummins = bigger harvest
cons: Heat, increase cost in electricity

But if you do the math the average cost of a killowatt hour is $0.08 lets say you run 2- 400w HPS lamps that is 800watts that = .8 killowatt hours per hour. that = $0.07 per hour the light is on so a 4 week veg at 18/6 will cost $37.80 the cost of the 8 week flower cycle at 12/12 will be $50.40 for a total of $88.20 for the entire grow cycle.
Now consider your increase in yeild. That will cover that cost without any problems.

Next if you are worried about big brother focusing in on you due to your increase of elec. This is less than if you plugged in a space heater, a space heater draws around 1500w. It is when someone decides to put in a greenhouse with say 6- 1000w lights is when big brother starts to wonder what is going on.

hope this is helpfull with your decision or any one else for that matter.
Jerry Garcia 2007 Reviewed by Jerry Garcia 2007 on . New Grow 1st time grow.Inherited some guerilla grow Big Buds.Already 6 months old and doing poorly. 4X8X8 room 1200 watts of 6500k cfl 7 gallon buckets Think the little ladies will survive? Rating: 5