You have to look at them as an investment. Both in electricity savings and the cost of new bulbs every year. LEDS win price wise in the long run.I am probably 3 years behind the curve since I JUST finally ordered a 12 bulb T5 fixture for my 125 g. Maybe I will spotlight with some LED's but when I priced out LED's for my 125...ouch.
It is hard to argue with the results people are getting with them now. I will say Warm White and Neutral White Cree LEDs are a must if you are building your own fixture. My frag tank is getting much better coloration then my DT and I will be adding the WW and NW to the DT as soon as I can figure out a way to do so.Seems LED is the overwhelming light choice.