Expensive, but many families spend more on physio and other professionals (150$-300$ per hour). When we are talking about children's health and future, parents will raid their pensions accounts, grandparent's etc...
Hopefully once they get more popular, the government will pay for it to setup in Rehabilitation centers. From what I saw right now it's mostly private centers that are buying it (US/Canada).
New tech is always expensive at first. Selling something for $1k/month is better than not selling it at all. If these things were easy to make cheaply someone would be doing it.
It doesn't always need to be expensive, but it also isn't always inexpensive upfront. And the comment you reply to makes a plea about the price.
Price doesn't mean you haven't changed a lot of lives either: In addition, a lot of folks that can't walk are covered by some sort of government-provided insurance. Unfortunately, it doesn't really help all that much because insurance limitations don't always cover everything or cover enough.
I'll also say that it is a lot for a single person/family: It isn't nearly as much at a daycare, school, physical therapy and other such things. I'd not be surprised if such places weren't their most common home.
$1k a month seems downright cheap compared to many medical treatments.
Hospital visits in the US average $11.7k for a full stay[1]. Antiviral treatments for Hepatitis C like Harvoni and Sovaldi cost $16k-90k for 12 weeks, though you can go with a generic version for $5k-10k a month.
Hopefully once they get more popular, the government will pay for it to setup in Rehabilitation centers. From what I saw right now it's mostly private centers that are buying it (US/Canada).