$10k/month in the US doesn't sound so far from truth. After health care and taxes (paying both sides), it goes pretty quickly.
This is absolutely true. I have a family with a númber of kids, two in college. I am paying taxes, health-care (25% thanks to Company benefits), VAT. If you have a house, #3 cars (no Porsch or Flying Emily) you cannot be anywhere below unless you want to be drizzled by liquid sunshine or lodge in Rainier valley.
Actually this was just a reasonable assumption for typical north-western US household (Pacific Coast, I left Walla-walla County). I don't believe that anyone here in my neighbourhood manages below, and this is middle - class, its not Queen Anne, Kensington or Beverly Hills.
So question remains unanswered: What do you call a living?
Also so far the key point in the post is missed. In mining you are always competing with a number of People. To maintain the rquired income a substantial part of the income has to be re-invested. As I said you have to have a certain share of the total hash rate to maintain the income. Now it may be quite easy to deduct 10% of the income and reinvest it into mining.
10% of 10k gives you 1k for Investment, I am not greedy lets make it 2k (So I only earn 8k$ for a living - Farewell Crystal mountain & Acapulco). Now you need 800 ppm of the total Investment not to loose anything:
2,000$ x 1,000,000 / 800 = 2,500,000$.
So thats the monthly Investment to be brought up from the other miners to drive me out of my premises. Given its 100,000 People out there and they buy 3-4 USB miner each month on the average, I can file for bankruptcy soon.