The Definitive Guide To Curved TreadmillsThis is a pretty good article on treadmills. However this is explanation is a crock of shit!
They are expensive and a real step up from regular treadmills. A good motorized treadmill will set you back around $1,500 and higher. Curved treadmills start at around $4,000 and most are $5,000+. It's because they're different from normal treadmills that make them so expensive. New technology takes investment and this is reflected in the price.
They don't have motors. They're simpler! Therefore, they should be less expensive!
LINK:
https://www.treadmill.run/definitive-guide-to-curved-treadmills.html