In my story mankind has spread a bit into space and has started mining asteroids. The resources from this, combined with advances in automated manufacturing allows Earth and all her colonies to become a post-scarcity society. This is great for the man on the street because even the "homeless" still live in paradise. However, this is not so great for me the author, because I have a piece of technology that only certain people can have. It's called an Interface, and it's a neural implant that allows easy interfacing with a variety of equipment and robotics. For example my MC used his once to send a cleaning robot to a different room because it was bugging him, then another time he disconnected from his own vision, and used his rocket ships sensors as eyes and he was able to see radar and x-rays. It also works as a communicator, he can talk through it, when he opens an email it appears to float in front of him, ect. So, you can see how this would be useful, and how basically every person in the solar system would want one. The problem is, I can only have two of my characters have them, but in this post scarcity society anybody who wanted one would be able to get one. So I need to come up with a reason why people wouldn't want it, or figure out some way of making it too expensive for the average person. I've come up with 2 potential solutions. The first is to make it into a very high skill procedure. Since goods and resources are so cheap, what will really have value is services. If neurosurgery is still only performed by human neurosurgeons it could drive up the cost of the interface. But I'm worried that this might confuse the reader unless I just infodump about the economy. I don't want to do that though, because the reader doesn't need to know anything about the economy. My second thought was to instead make the surgery a huge ordeal that people wouldn't want to put themselves through. I remember reading some where that patients are kept awake for brain surgery. This would probably be very disturbing if eyes had to be removed from their sockets so implants could be inserted. If the surgery takes several hours to perform, do you think people would think twice before getting it done, considering all the benefits that come with it? I guess there's some cons as well, the hardware can never be upgraded or installed over for instance, but would you get one? Keep in mind the surgery itself is gonna be painless. It's the future after all. I'm open to any thoughts and suggestions.