I always have to tell people telling me how much I'd save by switching to LED that it would take me 4-5 years to recover the initial costs through electricity savings to replace my HID.
Cooling and the supposed increased yield potential compared to hps is the main reason I want to move to them in the future, but for now mh in veg and hps in flower works just fine. 2 of my gorrilla glues.
I definitely wasn't prepared for the electric costs with my current grow. Shits been rough, but I know I'm looking at nearly double the running costs with these upgrades.
Now that I think on it even more I'd probably be best off switching to 6 600s not a huge increase over what I'm using now as far as power consumption. I'm already equipped to handle that much cooling but I'd get significantly better coverage with nearlythe same running costs. Yep that settles it.