200 watt cfl

So Ive read and read about everyone talking about how many CFL bulbs they are using in their grow. Now its time to start my own, and I am coming to realize that the cost for one high wattage CFL is lower than the bill for multiple bulbs. So, here is my question, Which is better for a grow of...

Is a 65watt cfl that puts out 4200 lumens good to use to germ/veg. I also saw a 42 watt that puts out 2800 lms. My gut says buy the biggest, really want to know what you all think. Thank you