Bitcoin Forum

Hi mining friends,
first at all, i'm coming from german coin boards but could hardly find any answers, so please excuse potential bad grammar and simple english.  :-X

With the recently high profit ranges of mining ETH and many other alt coins i ordered hardware for a small mining rig with 5x RX580 8GB (est. shipping mid july) just for testing and hopefully a bit profit.
Now a friend of mine permanently asks me for going bigger, maybe 80x RX580s (should be available again in a few months). We have some commercial rooms in an industrial building with electricity inclusive, so no extra costs for the rigs.
With the data from whattomine.com i've calculated some profits with eth only (other altcoins are equal in average):

last week: ~5,50$ / Day / RX580 - would be 440$ / Day with 80 GPUs or 13.000$ / month
today: ~3,80$ / Day / RX580 - so 300$ / Day w/ 80 GPUs or 3.000$ / month

This profit drop should be the result of the exponential rising of the difficulty in relation to the higher numbers of miners in the last months, or am i missing something here?

My question to all of you, but especially the big miners is, what do you mean how far this drop / crash in profits will go until it stagnates for months (when most of the hobby miners switch to other alt coins or sell their equipment because of the electricity costs)? This questions applies of course not only for eth rather for all alt coins with all the switching miners.

In my opinion the worst profit / day for a RX580 will be about 1$, at this point the most hobby miners will go. Do you guys have the same estimations?
In this case, would you invest about 25k $ for 2.400$ profit / month? (11 months ROI sounds okay for me but after that, 2.400$ earnings / month is not the greatest thing since sliced bread - apart from possible taxes and fees)

Would be great if some of you could give me feedback for this project idea and sorry again for my bad english  ;D