I wouldn't say that gliding is free. At the club that I fly at and will be soon instructing, the buy in is $600, annual dues at $500, and tows range between $18-$25 depending on altitude.
$400 buy in at our club, and $40/mo. But you can go inactive as well, so the dues only kick in when you are actually flying. Half price for students.
It isn't free, but it is way cheaper than training in a Cessna. It may take longer, but if you just want fast, go to a 141 school. About $25/hour is what it has worked out to for me - the 172 I rent is $150/hour.
An important thing to keep in mind is that once you have your commercial or CFI-G, you won't be paying to fly anymore. A commercial glider ticket is pretty easy to get (200TT or 100 glider flights). Of those 100 glider flights, a good chunk will be $15 sled rides. We always have students waiting for a CFI-G to go up with, or guests for intro flights. You can conceivably have your CFI-G at less than 50 hours TT.
Most non-pilots I know describe a soaring ride as one of the best experiences of their lives. While it won't make you rich, it can be very rewarding introducing people to aviation in its purest form. We usually have more people waiting for intro rides than we have commercial pilots to do them.
Our CFI-G's are so busy that most haven't been up on pleasure flights in years. Most clubs either give free instruction or close to it ($20/hour at ours). Bad soaring days are ironically the busiest for the towplane, as they are good instruction days
Some other points if you do the glider ratings first:
- You will probably do your PPL ASEL at the bare minimums if you already have your commercial glider. On average, that's going to save you around $3,000.
- Your stick and rudder flying will probably be as good as your airplane CFI's.
- You will never hear your CFI say "step on the ball."
- Engine-out emergencies won't scare you (as much).
- Volunteer tow pilots are always needed at most clubs (more "free" time if you want it).
- There is a good deal of camaraderie at glider operations. 2 hours in the logbook is an all-day thing. Getting gliders in the air is a team effort - staging, wing-running, etc. BBQ and beers at the end of the day is the norm - it isn't like and FBO where you show up, fly, and leave.
- Anyone with a checkbook can X/C an airplane 300 miles. 300 X/C in a glider takes good ADM, a good stick, and a lot of knowledge. i.e., The Right Stuff...
- It'll make you a better pilot.