My main question was if I could get at least a ROI for my rig if I start mining right now. that's what worries me most 

Is mining btc still profitable?

Hi everyone, I was interested in buying 5 RX570 for mining ETH. I have free power so this won't be an issue. I have seen using the ETH mining calculator that in 6 month I will make 3000$ but this will be true just if ETH will not be harder to mine in the future. So I was wondering, sooner ETH will move from PoW to PoS, in that case I won't be able to mine anymore ETH. So is it worth to build a mining rig now, mine ETH until is PoW and then maybe mine other currencies? Thanks!