I think we should really fix society before we develop that kind of technology. We need a socio-cultural breaktrough of the same magnitude as the technological breakthrough. Something on par with the development of monotheism, enlightenment, capitalism, or democracy. A "communistic" utopia (for lack of a better word) without the flaws of its historical implementations. Then the question is moot. There is no private business, or indeed any other entity, government or private, that you would make such a
deal with. There is no second party that wants to withhold technology, or steal your thoughts. Rather it will be "From each according to his ability, to each according to his needs" - you get the augmentation for free, and you contribute what you feel comfortable sharing back to society.
Often, utopia is portrayed as the result of a technolocial breakthrough, sometimes "if we could read each others thoughts there would be no misunderstanding and conflict". I believe it is the other way around - utopia is a precondition for singularity-type technology. At least, if we want it to be beneficial and not hellish.
Brain implants are easy, communism is going to be hard.