power cost at 9 cents is about $ 3.07 a 49 cent profit
power cost at 8 cents is about $ 2.73 a 83 cent profit
power cost at 7 cents is about $ 2.39 a $1.17 profit
power cost at 6 cents is about $ 2.04 a $1.52 profit
power cost at 5 cents is about $ 1.70 a $1.86 profit
power cost at 4 cents is about $ 1.36 a $2.20 profit
power cost at 3 cents is about $ 1.02 a $2.54 profit
Same thing can be said about alt coins mining. Imagine those retail miners like me which only have access to power cost of about >10 cents. The coins earned from mining just barely cover the cost of electricity, let alone the cost of the mining rigs. Mining just doesn't make cents anymore unless you are industrial miner with access to really cheap electricity near the source, like what the China mining companies do.
2 years ago, the most common argument we heard about the main advantage of mining (a.k.a solving cryptographic quizes) is its more decentralized and can prevent 51% attack. Not sure if thats the case now. Mining seems like a power play of the few giants. I really wonder what will happen for mining in the future when only a few have the controlling resource (i.e. hash power) in the entire network.
It seems to me, staking (or variation of staking) is the way to move forward.