1100 euro for an unpowered treadmill seems excessive unless you’re going for the craft treadmill market(is that a thing?). The problem I’ve had trying unpowered treadmills is either they have too much friction causing them to be a lot more work/tiring or they don’t have enough and then you struggle to balance. I got my first powered one off amazon for like $150aud so less than 1/10th and even that was quiet enough, though I wear headphones. My current one is a bit more expensive but it folds in half for storage.
I expect they’ll get a few sales but I’d be surprised at even a 1% conversion from the wait list.
When not walking(rare) I use an Aeron for work and at my electronics lab desk I just use a simple wooden chair I’ve borrowed from my dining table(accidentally bought a 6 seat dining table and live alone I have some to spare).
I’m also known to sit in my recliner and work sometimes too.
I look a lot cooler in my head for sure 
I should probably stop advertising the url