Like others here, I'm afraid I don't see the point of the poll and so I didn't participate in it.
Biggest problem with the poll, I think, is that it equates earning money with whether or not a person is a serious photographer. I don't earn a living from photography but my interest is more than "just for fun" as well. For me, it is primarily a form of personal expression, primarily through documentation of the world, its people and my journey through life.
Ultimate success for me would be to leave behind a legacy that lasts long after any profits have been spent.
As far as the potential cost of a 7DII, well that's a personal decision that everyone must make. It will be driven by budget, interests, desires, etc. When you read that people are willing to spend nearly $1,000 more than the current street price of the 7D you have to realize a few things.
No one wants the camera to cost any more than is necessary. But, it is a testament to the quality of the 7D that many owners (myself included) are willing to consider paying a premium for a new body that is even better than what we consider to be an excellent camera right now. I think people are trying to be realistic about pricing and preparing for the worst, having seen the price inflation of the 5DIII.
For everyone, there comes a point where the perceived value is not enough to justify the cost. I think people are just trying to articulate where that price point might be for them.
What I find interesting is that most 7D owners on this forum are pretty consistent in what they want. If you were to draw a graph of expressed desires, the bell of the curve would congregate around improved sensor performance and modest upgrades to what is already very good autofocus and build quality. In contrast, higher resolution appears to be somewhere on the toe of the curve. Most 7D owners expressing an opinion on this site seem to be saying they would not object to higher resolution, but only if it doesn't come at the expense of overall sensor quality.
I am an optimist. I think competitive pressures will keep the 7DII within a few hundred dollars of the original 7D's price at introduction. I also have in my mind a pretty good idea of what it will take in terms of features for me to upgrade and how much I might be willing to pay for those features. My belief is that I am a fairly typical 7D owner and that since Canon wants our money they will deliver.
If they don't, well, I still have a great camera in the 7D.