CC are probably the cheapest lighting you can do. But I don't think you can grow plants with them. It's something I want to test in the future though. Wiring the two blue ones for moonlight on to my 55gal cost $10. I have 6 blue CC in my car to, I forget how much just the CC cost, I put a lot of lights in my car.
When I'm able to have my own fish room, I will plan to just use white CC in series to light tanks. It would be easy enough to do and save on electric costs. I've yet to test how well a white CC lights in an already light room. With the blue ones, when the room light is on, they don't look like they are making a lot of light.
LED's I've never worked with, but seem more complicated than CC. CC you just by two tubes and a inverter, usually comes with a molex connector for computers. Chop the connector off, find a AD/DC inverter and cut the end of off of it. Strip 4 wires, attach the two wires from the cc to the two wires from the AC/DC inverter. If they don't light switch the wires around, then presto light!