Very much the case! (Well, idk quite what gp imagined, but it's not as expensive as many things.)
When I was learning, around 2020, I budgeted ~$300 / month for glider flying, + ~$600 (I think: they've gone up!) for annual club dues. These days the monthly would be a bit higher, and the dues more like $700-800, I think. Flying as a club member is a lot cheaper than rides; you pay for the tow and for time on the aircraft, but aircraft time is way, way cheaper than power (no fuel to burn, no engine to maintain) and the instructors are volunteers.
NB this is in a club environment. The upside is that it's cheap and the club environment is a really good place to learn by osmosis / watching everybody else / listening to stories / seeing all kinds of different situations. The downside is that it's a huge time commitment. You'll drive 1.5 hrs and hang around all day to get twoish flights, sometimes < 10 min. each. And you have to be willing to commit all of every Saturday (or Sunday) for a year plus: you need to be flying just about every week, and given that some weekends'll be weathered out you have to be ready to take advantage of every flyable weekend. Folks that aren't committed just don't make progress: hang around, season after season, still flying with instructors, until they finally give up or just occasionally grind it out.
(I did the bulk of my training in 2020 and spring/early summer 2021. This was perfect: I was single and newish to the area I was living in, and thanks to Covid I had nothing else going on in my life. Even as things started to reopen in 2021 it was easy to maintain that "saturday? of course I'm at the field" habit.)
This is all harder to do as a Real Adult with responsibilities. Some folks manage to do it, but it's harder. Commercial operations, where you go and get a whole bunch of flying in relatively quickly, are also an option---but I hear there's a wide range of quality, and even the best won't get you the seasoning / airmanship you get from hanging around at the field every weekend for a year, flying in all sorts of conditions and taking advantage of the unofficial ground school from all the other instructor/student pairs there at the same time.
The economics change first once you've got your rating, when you're no longer doing short training flights and the bulk of your flying is (one hopes!) longer soaring flights; and then again when (if) you buy your own glider---but it's still that few thousand bucks / year order of magnitude. Expensive, but doable, especially compared to power.
Gliders themselves range from "surprisingly inexpensive" to "less expensive than a new powered aircraft", more or less. I'd expect to hear something like $5,000 for a Schweizer 1-26 (https://en.wikipedia.org/wiki/Schweizer_SGS_1-26: classic glider, still widely flown by a devoted community, but appreciably lower performance than gliders built after the massive jump that came with the switch to fiberglass); I have a part-share in a Jantar (https://en.wikipedia.org/wiki/SZD-41_Jantar_Standard, early fiberglass) that totals $25,000 or a little less, with reasonably nice avionics.
So, all told, yes, flying gliders costs a meaningful amount of money, but isn't terribly terribly expensive. The question to ask yourself is really not whether you've got the money, but whether you've got the time.
These guys had a big oxygen tank.
It's nice to see they were using an Air Glide S and managed to make their goal against the odd 56kt headwind.
IBM had a tradition of not allowing customers to fall down. JES3 took down a bank in Buffalo. Fortunately for the guilty a major snowstorm had shutdown the city for several days. IBM sent in SEs on snowmobiles.
COLT was even worse as it could throw a mainframe into an interrupt cascade. You had to press System Reset, then IPL and pick up the pieces of transactions. It took me a few months to identify where a register got mangled over an interrupt. This was pseudo reentrant code which I came to utterly despise.
I characterized the code as the result of student intern self abuse.
I spent several months flogging that dead horse until I changed jobs. There were later opportunities at other banks that saw COLT on my résumé that I refused.
In the current millennium, IBM has been serially fomenting payroll disasters with Phoenix as it's known in Canada (I don't know what it's called in Australia).