Philips won a $10 million contest run by the US government, the L Prize from Department of Enenrgy, to build the best (theoritically) eco-friendly and affordable LED bulb.
The prize-winning LED bulb will soon be launched in the US market, and cost $50. In comparison, the plain old energy-hogging incandescent bulb costs $1.
But, consider this: The LED bulb will last for 10 years, use only 10 watts, and give light equivalent of a 60-watt bulb, and save you $100 in your electricity bill over this period.
However, there are comparable LED bilb models that cost less than the $50 light bulb, so it might only be a luxury item.