Not sure where you live, but if you go to your local big box hardware store, you can get a light fixture cheaper than that, look for one with reflective "wings " on it.
And if you have the fixture, you might as well use it in the flower stage too....more light the merrier!
Using the CFL's in conjunction with the fixture will be best.

Take a look at the links in my signature to see what I did with the CFL's
I use a 400 watt HPS and still use CFL's for side lighting.
Also, use the opposite spectrum on some of your lighting....full spectrum is the way to go