t5 Fluorescents vs HPS, HID, or MH?

I started growing 2 white widows about 1 month ago, and I am currently growing them under 2 t5 Fluorescents. I like the fact that the t5's are energy and cost efficient, but I want to switch to brighter lights for when I flower them, but I also want to save as much energy and money as possible on my electric bill. How much more energy and money do the HPS or HID, or MH lights cost? Are the costs almost the same? Plus, I don't care about the heat differences.
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An HID is a High Intensity Discharge lamp. High Pressure Sodium (HPS), Metal Halide (MH), and Mercury Vapor are all HID lamps. Grab your electric bill and do the math. Multiply the killowat hour cost by the energy you are intending on using and there you go. A 600watt digital ballast and lamp (firing HPS and MH) can run as little as 25$ a month maybe less depending on how often you run it. One way or the other you pay for it, what I mean is that it might take 30 T5s to get the same power and light to produce the yield of a 600watt grow.

I run 2x 400's and a 600 along with all the pumps and goodies to run 6x 4 bucket rwdc systems. This includes 3 a/c's and it adds about $150 to my bill but rates differ all over the place so do the math as suggested above for the exacts.

As for growing,....hps is where it's at. Heat isn't an issue anyway because the amount of cfl's you'd need to equal a small hps, would generate about the same amount.