I have 3 RX580 4GB and they have been mining at 29 mh/s for almost 2 months now. I didn't see a drop nor and increase.
GPU mining wont be profitable soon, save up and wait for FPGA/ASIC. They will be expensive.
ASIC D3 seller tell me that 150$/day but when i got it 2x$/day and will be 1x in next month...
The problem with Asics is they are far over priced for the hardware that is inside and by the time you get yours another 10,000 other people got theirs and the difficulty sky rockets from where it was when you priced and did your ROI calculations
GPU is still profitable, atm the issue is the up coming Bitcoin Fork, it is driving people to sell all their alt coins to hold Bitcoin in hopes to gain free coins in the form of bitcoin gold. Similar happened with the Bitcoin cash fork, coins bounced back however. After the fork however be prepared for a possible plunge in Bitcoin prices as the current drive up in price is due to the same reason as the fall in alt coin prices