Fair enough comment, I didn't add much detail. My thoughts are: The market for a useful cybernetic limb is extremely small, despite the amount of media attent

Fair enough comment, I didn't add much detail. My thoughts are: The market for a useful cybernetic limb is extremely small, despite the amount of media attention this kind of thing gets. It would be limited to injured soldiers, the very small number of civilians that lose limbs, and the even smaller number of biohackers that would consider voluntarily replacing a limb. Each prosthetic limb would need to be custom built to size constraints and other characteristics of the amputated limb. Think about how much effort it took to create a good consumer experience for a smartphone where the market size is essentially the entire population on the planet and there are massive economies of scale. The other factor is that even the limb prosthetics we have today require a significant amount of ongoing support to resize and adjust to the user. You can appreciate therefore that a highly sophisticated and customised synthetic limb would require very thorough ongoing follow up and maintenance for the lifetime of the user, and this incurs a significant cost. Another factor is competing technology - growing organs extra-corporeally benefits from a much broader scope and therefore larger market, and possibly even easier engineering hurdles. Also, it is likely that there will be robots which you can ask to pick up your coffee cup etc long before a useful prosthetic limb. This isn't as good as having your own arm, but the engineering hurdles are much easier and the market for robotics is obviously massive. I would suggest therefore that in the next 30 years, a useful prosthetic limb, with acceptable latency, strength and durability is probably not possible for less than several hundred thousand dollars initial cost, and perhaps that much again for life long maintenance. I also doubt that the potential market is big enough for someone to invest enough to turn it into a really good consumer product, including setting up supply chain and maintenance systems.