There are different depths to fitting -- for $30 to $60 you can expect basic measurements (crotch height, torso length, arm length, feet length); bike adjustment (seat height, seat fore/aft, recommendations on top tube / cockpit length based on fit formula and a short trainer session). The cockpit length (butt to hands) is the most difficult to adjust, and the standard $50 fit is just going to spit out a formula based on your measurements and the riding angle input into the program. I generally ride at a steeper angle than input into the system, so my cockpit was at the upper limit of suggested cockpit length. This is where having a better LBS to work on this aspect of fit is extremely valuable.

I did the basic fit at a Specialized dealer (their advanced fit system is based on the Andy Pruitt / Colorado Medical Center fit program, I don't know about the basic $50 fit). I wanted to have accurate measurements (warning: you have to ask special for these, it is not part of the printout, which just has the "results".) It was also a fast way to get the seat height dialed in, because I don't know ppl that can stand around watching my butt on the trainer. There was not much trainer work, so there was not much useful information on the reach adjustment / cockpit length. There is an issue with my left knee collapsing inward slightly (sigh, collateral damage from an upper tibia stress fracture in my right leg that I've been working on) - I knew this was a problem with weight / balance training, but it was affecting my pedaling also, so now I have in-shoe shims. So that alone was valuable, since I like having working knees.

Talk with the LBS about what their $25 fit entails. My ideal would be to have measurements, start with a "stock" setup from a fit system that I understand and endorse, then lots of trainer time to really dial in the fit. Unless you are paying in the $150-250 range for motion capture / laser points / etc., then any fit is going to basically get you in the 2 cm range, and you need start tweaking yourself from there. So $25 is a bargain.

Information that I wish I had: % weight on fore / aft wheels (need to find another scale for this); more information on ideal crank length, since with a 32" / 81 cm inseam, suggested lengths range from 165 mm (TA) to 175 mm (inseam in cm * 2.16). I have 170 mm on now. The most important thing I'd like is better cleat alignment, which only comes with expensive fits, or presumably helpful LBS.