The important thing to remember about LED's is the money you save long term. a 2x250W MH setup can run you alot of money over the course of a year
$100 in bulbs
With a 8hr photo period
500 X 8hr a day X 30 Days a month X 12 months a year = about $144 in electric
Thats $2440 over the projected lifetime of a LED setup...