According to rise of difficult of mining.
I must say it is so hard to earn some real cash from doing it.
You invest for example $2000, it is not a lot like for mining hardware, but for most of us it is quite large investitment.
So you spend 2000$. If difficulty will not go up (not possible) you will have your money back in about 4 months.
If your mining hardware will not fail.
But difficult will rise. So time to get money back will add to 4 months and it is gonna be (example) 6-7months.
So
The only good way to start mining is invest 10.000$ - 15.000$ minimum.
Then we can talk.
It is getting to be harder and harder
Like it should be. But... i just say - soon normal user will be not able to mine in reasonable investitment price.