It is not only the PAR, the ad actually says in the specs: "13W : approximately equal to the blue ray of a 195W incandescent light"
By that statement I assume that they are measuring the blue spectrum of the output against a "warm" white incadescent and not the actual light output.
Anyhow, as an example of just how far off of useful this light would be for growing coral I would point you towards
http://www.marinedepot.com/ps_viewit...TFILDTN-UU1111 which is a LED fixture with almost the same measurements as the one on ebay. It uses 90 Watts worth of LED's (Likely the fixture would draw more) instead of the 13W.
As another comparison
http://cgi.ebay.ca/High-Intensity-10...item563a9a1174 is a flashlight that takes 3 AAA batteries and draws 10W for the LED output. It would be difficult to hang a flashlight over an aquarium and expect anything to grow... (Yes, not a perfect comparison- but it gives you the idea.)
I think that if you research the DIY fixtures on these boards you will get a much better idea of the kinds of power and the types of light (including spectrum) that is necessary for a fixture to be usable and it will make it easier for you to form your own conclusion about light fixtures.
Good luck.