Most of those "business owners" have some sort of a tax angle going on that makes their hobby much more affordable.
I wouldn't say "rubber powered FF" is cheap. Contest rubber is $24/lb., and that's if you buy 10 lbs at a whack. Each motor is generally good for one flight if you are serious. If it survives, you won't get max power out of it on the next flight, or it will break, but you can use it for practise, if you ever get to do that. I bought 10 lbs of Champion Rubber and 10 lbs of FAI Supply (Ed Dolby vintage) and none was worth flying. I guess it's a lot more consistent now, tho. But you'd be lucky to get a dozen motors out of each pound, I'd expect...$2 each.
HLG (Hand Launched Glider or "Hurl Glider") was the ultimate cheap hobby, but now, to compete, you are looking at a lot of CF, Discus Launch and both DT and Transponder Beacon technology...not cheap. And of course, going to a contest costs just as much as going to fly any other (more expensive) events.
Going to a contest in your Honda Civic or equivalent isn't real cheap these days. Our contest 'circuit' ranges from 3 hours N. of Seattle to 3+ hours South of Seattle. Most of a tank of gas for most vehicles, each direction. Best to keep your expenditures as low as possible, and not to even think about it. Otherwise, you won't go, and will miss out on some good times. And there are others off the beaten path that are farther away...Mark, Pat, Bruce, Bryan, JT and Russell fall into that catagory.

Steve