Reply #13: Lifespan is key

[Literate Dragon]

The LEDs cost more than incandescents but you hardly ever need to change them. It's not just that they use less electricity but they also last much, much longer. A 100-watt incandescent might need to be replaced three to six times a year, while I have had the fluorescent replacements, which use 25 watts to generate the same light output, last for two years or more. So in effect drop the initial price from $20 to $2.50 (because you're buying the equivalent of eight incandescents on the average), and then slice your light bill by 75% over two years and subtract that from the price.