What work is needed after initial set up? I thought after initial setup miners doesn't require a lot of attention if they are reliable?

I'm mainly concerned about increasing difficulty more than 10% every month and reliability.
If Avalons are reliable than it's only difficulty.
I think with $0.02 electricity cost it is still no brainer to invest in mining?

Thanks for your reply.

Yes I get that, operatonal cost, electricity cost and etc can be easy counted. But with difficullty increasing 10% every two weeks will it keep increasing like this? It's hard to calculate profitability with this fast growing difficulty numbers but if 14TH/S makes ~$300
minus operational costs I can't see how this wouldn't be profitable with cheap electricity?
I don't get why so little poeple jump into this mining business who have cheap electricity. What other legal businesess generates ROI in under 1 year that easy?

With more reliable Avalon maybe it's wiser to choose them instead of Bitmains S9? 2x Avalon 741 has the 14.6 TH/s and can be bought for ~1400USD from canaani.io

Hello.
I read as much as I could find about mining and still have couple questions and ideas I'd like to ask.
As I understand main thing to make profit in mining bitcoin is electricity cost. I have it at $0.02  so I'm expecting huge profits from it and ROI in 6months. But is it really that simple as it looks like?
Can I expect to run that farm for many years successfully with reinvesting large share of profits at the beggining? What you believe will be value of bitcoin in 2years? 5years?

How to correctly calculate increasing mining difficulty and which mining profitability calculator to use?
Most of them shows ~$350 profit per month without cost of electricity with Antminer S9 which sounds too good to be true to double up investment in 1 year.
But https://bitcoinwisdom.com/bitcoin/calculator shows that with S9 numbers it will be no profit in couple months with 10% Difficulty Increment. And I read that difficulty could increase more than 10%. So is this correct and all miners will become unprofitable in next months? How mining farms are dealing with it?

Which miner to choose for that investment? I'm thinking to buy about ~100 Avalon 741 miners directly from canaan.io since Antminer S9 is always sold out and I read they have a lot of issues with reliability and Bitmain support isn't the best to deal with.
I'm looking to get as much TH/s as possible and don't care too much about cost of electricity cause I have it cheap. But with Antminer S9 if they're not working 24/7/365 maybe Avalon 741 is more profitable in long run?
Is canaan.io legit? Does anyone had orders for $20k+ with them? Do they accept bitcoin for payment?


Would be nice if someone could share their experiences or ideas