cfl's work best in a cluster, a lot of people put thier cfl's super close.. heh. if you have too many it will burn just like a HPS. Im using about 14 cfl lights (only) they are all 23w 1750 lumen each which equals to about (25,000k lumen) 322wats and the results are amazing & the best part the heat is super low. my setup is about the same as a single 300w hps light with much less heat. You can get 150w HPS lights now for around 80.00 usd
I think my cfl setup cost me about 35.00 to build then what ever the cost of lights are. normally 10-15.00 per 4 pack. one cool thing about cfl's is you can take away or add more at any time. when i vegg i prob use 4-8 lights, then add more as they get bigger.