But at each of these discontinuities in block bounty, the supply/demand situation changes. A lot. When there are half as many per unit time being created, that will create pressure for appreciation.
It will also create pressure for significantly higher fees. If people aren't willing to pay them a lot of miners will stop mining, and the network will get much less secure.
Right now something like 95% of miners mine on pools, and none of the pools payout from tx fees. Unless this changes, there is no pressure for fees to do anything.
I am not sure why people are overgeeking this into obscure numbers.
5. Forget magic numbers.
I tend to agree, I don't really feel like there is much need for a magic number. Work out how much profit you are comfortable making and decide that way.
I'm personally considering dropping out already even though I'm way above/below a magic number, and I'm still making more than electricity costs, simply because electricity costs an arm and a leg here, and the hassle and noise and heat of running mining is approaching a level of not being worth it for me when half the money made pays for electricity, even though techincally I'm still getting a fair amount of "free money".