I’m unclear why you expect people to pay new prices for parts that have been fitted to a bike. I’m not looking to buy but if I were I’d spend the same money on something boxed from a dealer where there was comeback for issues.
Husky use a mount off the rear set for the exhaust mount on the 401s. I doubt it will fit the KTM as the foot pegs are different but it should be possible to copy the idea.