HID is much better than CFL. But you can flower a good crop with CFLs. It's not like it's "not worth it". You can still grow quality buds with CFL its just not as good as HID, obviously.
Day 25 of flower using 2 CFLs on 5 good-sized plants(not by choice). I would recommend you break up that fixture you have and get those bulbs by themselves. Now you can begin surrounding your plants with light. You want each light to be 1-3 inches away from your plants. You will have to re-adjust them daily, possibly multiple times per day. But this is the price we pay for using weak lighting. Don't think it's not enough, though. It's just not ideal.
That being said, if you aren't in my position, and you have around 100 bucks to spend, I would highly recommend getting an HID setup. You can find one on craigslist for around 100 just about any day of the week. (at least where I'm from thats how it is). The investment is worth MUCH more than 100 bucks, for the amount of improvement you will see.
If you are like me though, and cash is THAT tight that you can't go out and drop a bill on a new light right now, don't get discouraged. Growing quality buds with CFL is NOT impossible. It's much more work and much more time consuming, but it can be done with great results. If you have any questions feel free to send me a message.