Actually, a great idea. I had thought of this before as well, but seemed like it's antithetical to the platform with the whole 2 year lock in and to make it the investment aspect.
SP as an exclusive platform acquired token, would be like Rep. You can't buy your way to Rep, so too for SP you would not be able to buy your way up the SP power ladder. You have to get others to upvote you. It's more tied to the community this way. It has pros and cons, but overall it's making it more valuable indeed. And no one would want to Power Down since you lose your standing that is harder to earn.
It's an interesting thing for sure, I don't know of all the downsides though... heh.
I like the way you think! Although I wouldn't narrow it to just "Reputation"because thats only one aspect of social capital.
Thanks. Hehe... nono... I was just making an analogy as to how it's acquired, i.e. you can't buy it. ;) Not that it will be the new rep.