Go to home depot and take a look at what they have for 100 watt cfl's. Not the 100 watt equivalent cfl's but an actual 100 watt input cfl. I noticed the last time I was there that they started to carry a 80 and 100 watt bent tube cfl about 18" for about 25 bucks or something. That was without ballast but I dont think they are fetching much for the ballast either. It's a socketed type of bulb and will require a special socket even though it looks like a normal one. I just checked their website and it doesn't look like it's listed online. I found them over by the flood light section. Go see if yours carry them...if I had found them starting out I would have certainly taken this advice.