That's not a very exciting price for LEDs, though it beats Radio Shack if you need to get some in a hurry (as long as it's around Xmas time
The LED in your pictures is different from the ones usually found in the surplus market: it has that concave conical top that tends to disperse a lot of the light to the sides, which is nicer for some purposes than the narrow-angle point-source style that's more common in high intensities.
The sockets and diffusers might be useful for other projects. What sort of wire are they using in the string? I'm guessing that, given the price pressures, they use something really fine (and probably not very durable) to keep the cost down.