This looks like a very cool project and I'm happy to see it.
But please, to the author: give us some real price comparisons! I don't know how much a wheelchair costs. After reading this article, I still don't. Just be crystal clear and say "a simple manual wheelchair, approved by insurance, is often $4k, with $1k paid out of pocket" or whatever.
From their front page : "For more than three decades, New Mobility has published groundbreaking content for active wheelchair users."
Fair from them to assume the (average) reader is familiar with the subject.
You're in the right ballpark, though a good chair can easily get you into the 5 figures. Top-end is perhaps $20k.