I understand and even believe that a certain amount price manipulation is taking place in the bitcoin space; however, your outline of a mining scheme to manipulate price for its own benefit and worth the cost of doing business seems to attempt to minimize the number of players in the bitcoin scene and the expanding bitcoin market. Your attempt to simplify and to minimize aspects of the bitcoin community is much more complicated than the more likely reality that there are a variety of players and miners are not significantly selling to themselves in any widespread way.
People who invest millions of dollars don't like uncertainty. They analyze an opportunity as thoroughly as they can BEFORE investing (due diligence). Right now Wall Street and Silicon Valley investors have pumped billions into bitcoin. I think it's safe to assume that they:
* know more than most of the beaters posting on this forum
* see an opportunity for financial gain
* want a "first mover advantage" in the space
Wall Street types make millions per year in markets by arbitraging, manipulating, shorting, etc. This is what they do. You can be certain that there are many players in the bitcoin space using every single trick that financial types currently use, plus all of the tricks that are currently ILLEGAL in the mainstream financial system.