@Cereberus Yes it is legit. You can make even more when you overclock your AMD RX 580 8GB GPU. I think the profit you can make daily depends on some factors, like difficulty, people who are mining the specific coin and your electricity cost. However I suggest you to buy RX 580 as it just needs 2.5 months to ROI as you can see for yourself there. I use Nicehash to mine in all my mining rigs and I can confirm it is legit.
Which currency I should mine and how the earnings will be? I'm confused.
How to build a My Computer which will run 24/7 and make money?
I must need to purchase Instant Power Supply for Electricity Backup but also need the PC to be cool always as it needs to run for 24/7.
If you don't care about the coins you will mine, keep using Nicehash miner, because it converts your "coins" directly into BTC. The earnings depends on the difficulty and the hashrate you got..
You can simply use your "gaming" computer if you have one --> install Nicehash, set your BTC wallet and enjoy