I hear the figure 30PH/s tossed around for this coming January. Then to stay current we need to buy 10x the hashing power we have now. Ouch.
to stay current, you need to double the amount of your miners with every difficulty rise
Double? Impossible of course.
But looking at hashrate versus earnings, double the hashrate and halve your earnings for a given hashrate. So, if the network hashrate hits 30PH/s in January and it's well over 3PH/s right now, then just to stay even one would need at least 10x the hashrate just to earn the BTC one earned today.
Get that? What's impossible even with the 10x scenario is that it will only earn the same BTC/day that one is earning now - and how much would it cost to increase one's hashrate ten times? And to get delivery in January, when would one need slap down the coin for the equipment purchase?