This is a DIY from a guy in California, I paid $200 when I bought it, but now I saw on Ebay that he reduced the price to $185 free shipping whith improved features like dimmer and individual switch for actinic.
Edit: you can also link more light fixtures together, you just need separate power cable. check the topic at the new to the hobby forum that I started under the title LED lighting, to see a picture of 2 light fixtures linked together.