These are not the type of LEDs used in modern light LED light bulbs. They produce a tiny amount of light (maybe 5 lumens each, with a 60W equivalent requiring 800 lumens), don't work well with a heat sink, and aren't particularly efficient. Separately, a lot more goes into an LED light bulb than just the LED.
Home Depot has been selling those lamps for $4.97ea for quite a few months now. They're a very nice replacement for the traditional A19 60W incandescents.
My only complaint, and it's a tiny one, is that they only dim to about 10% before cutting off entirely. There's also a small dark spot on the spot of the bulb opposite the socket, but in practice that's been a non-issue for all my use cases.
In the US, the price varies state by state, and reflects a variety of subsidies used to encourage the switch over from incandescents. Thus for certain bulbs (like this one) the production cost is often higher than the selling price. Some details for California here: http://www.designingwithleds.com/rebated-cree-philips-led-bu...
Led light bulbs are considerably more intense. It has to contain a power supply, heat sink, and more LEDs than just the one that gets put into the single led, and all that needs to be interconnected on a chip.