And I bet they don't labour the fact that you need space to save you putting it up and taking it down, as so many have commented in this thread. There are many other ways of exercising that don't involve spending £500 and taking up a room of your home, if your home is even big enough for a start. And if like me, you've had any sort of surgery, you'll be directed by physios and doctors about exactly what exercises you can and can't be doing, sometimes for months. So if you're a potential customer for a joint replacement, for example, it's not a good investment.
So that narrows it down to the healthy, wealthy enough to have a spare room in your house where you'll be sheltered and warm, and fit, really.