Some math in real terms...
I just hit the 2.0 quadrillion hoard achievement which I had been saving for quite some time to get. Including the bonus for that and one I picked up for hitting 500B income, I spent a total of 2.215 quadrillion on new buildings yesterday. My income went up to almost 584B (from 445). If I don't buy another building, at my current income level it will take about 475 days worth of income to recoup that 2.215 quad. Obviously, with extra coin from the calendars, lottery, etc. it won't take quite that long in reality, but if I only relied on income generated every 42 minutes, that's how long it would take.
Edit: Oopsie! Bad math. 584B every 42 minutes is almost exactly 20 trillion a day, 111 days to recoup 2.215 quad (with 5 trillion left over)
Edit #2: The 475 days figure is relevant after all. I increased my profit by 139 billion per 42 minutes (at a cost of 2.215 quad). It would take 475 days for the increase in profit to pay for itself. In other words, 139B every 42 minutes takes roughly 475 days to make 2.215 quad. I essentially invested that pile of coin assuming I'd be still playing in 475 days to start making money from it. Put in real-life terms...I paid $2215 for an investment returning 13.9 cents every 42 minutes (or $4.76 a day).
Last edited: Feb 14, 2012