wow, awesome parallel from one of my reference designers. Nice sleek design. But there seem to be some design solutions that are at odds from our experience in riding jetpacks. We had to design things around function for sport, minimal solutions were preferred, but function ruled all decisions. A few great looking ideas just didn't test out.
Firstly, the weight of the body hangs from the jetpack when you fly and your legs swings side side to side and front to back, messing up the dynamics and CG. All that body weight has to be carried somewhere. Some designs from the 1960's use a two strap crotch belt, but those flights last thirty seconds, maximum, due to fuel. Comfort was not a pressing concern.
The 100k Euro German water thrust model uses a little flat bike style seat, the most painful experience imaginable being lifted up in the air by your crotch and the sharp edges, add sideways swing to it and I literally had bumps inside my groin for weeks afterwards.
Marc's design has two possible places for this weight to be suspended, the single strap between your gluteus maximii and family jewels, or on your elbows as in a vertical crunch machine at the gym. Either of these choices seem suspect in terms of comfort and control of the machine.
We developed a seat inspired by dressage horse saddles, allowing you to distribute the weight and keep the legs, 40% of your body weight, stable, and be able to grip with the thighs. Also automatically stabilizes the pendulum effect when turning great for learning. Integrated into this is the two strap design to take the stress off the centerline.
Secondly, steering in these machines is done by pivoting the vectors of thrust relative to the body CG. With a solid design as shown it is hard to see how forward or backward vectoring would be obtained. Side to side perhaps by thrust variation, however the thrust/turbine exhaust channel split looks symmetric without mechanism. Gyroscopic is defined but I am not sure how this dynamic would be achieved. It is true however that subtle movements are required.
Regarding price, several factors determine it. Low volume. No existing sales channel, distributor and retail margins have to support the new chain in order to build the sport. Competitive similar products, Flyboard and Jetovator are priced at similar range. Lastly we need the initial margin to innovate.
The othe guys 100k price includes a transplanted engine from a jetski.
I like your ladder! I have climbed many of those, sometimes icey in the winter, I did an internal visualization on the hand feel and foot feel of your rung design and liked it better. And I liked your details about the production and the kilometers of alloy extruded.