@current diff, 26$ can make R9 280x card in a month, electricity not included.
Wrong, with current diff you can make barely
60$ in a month with SIX 280x cards at 220 MH/s each one. If you are in a good variance run, good for you, but that's not real.
My calculations are based on previous 2-3 days, but as diff is rising, today stats are different, very much.
Your expectation is more realistic today. So I may say for today, you are right. Tomorrow will might be even worse.
Edit: My stats for today are: R9 280x makes 0.002 BTC/day - electricity cost.
It is 0,44$ per day - let's say price for electricity is 0,1$/kw = 24*150w=3,6kw*0,1=0,36$
Payoff is less than 0,08$ per day. Really bad.
That guy makng 26$ per day now must have 325 R9 280X cards running
phewwww....