How much? I'll bet the price will be high.
How dependable? The retractable tires make me think: "Needlessly complex."
What's the payload on land?
How well does it tow a trailer?
Is there a floating trailer available?
Payload of any trailer on land?
Interesting, but I'd be surprised if it survives on the market.
The Duck is proven technology, worked very well during WWII. Parts might be a problem though. That Quadski looks like something Q-Branch cooked up for Roger Moore! All it needs is some machine guns, missiles, and a submarine mode!