A proper fitting is dramatic. I paid ~$160 for my Wobblenaught fit I think. It would have been free had I bought the bike form the LBS that fit me, but I bought it at a very small shop that had the brand I wanted. I think that store (95% my fault) as well sold me a bike thats a size to large, but thats another issue).as someone else noted, the fit is both for comfort (and I am super comfortable and very aero as well) but equally about the hip angle, placment of sit bones, etc. to allow you to generate the most power on the bike.
To show how dramtic a chnage it was for me, I now find myself almost always on my sitbones and on the back of the saddle, whereas before I was always fidgeting around on the saddle pushing myself back. I tried to chnage all that myself and always made no improvements. The seats actually much further back and tilted down in front now-exact oppsite of what youd think!!
It has so dramatically changed what muscles I use that my first 5 or 6 rides were like starting over again!! Everytime the road took any sort of an uphill, it felt like I was using muscles I had never used before. Luckily and intentionally I did my fit when I only had 200 or 300 miles in after a long time off so I could easily make the adaptation.
Since the fit in August I have only made a small change (raised my saddle 2mm) because I keep mashing through the bottom of the stroke. The 2mm made a big difference and I also think my ave cadence is back up a few rpm as well.
Sorry-a bit long winded. My points being dont fit your self. Use the onlline fits to find a bike that will fit you, but if your serious about your cycling, do a fit. And this comes form a guy whod much rather spend the $160 on some more bike cloths, gadgets, but I am a believer now.
Ray