If you tell me how this miner will mine 8.5BTC I will buy one.
188 days with 14% increments will make 4BTC after that it will make 0.0077 a day.
You didn't understand my logic. I prefer to get a miner because I will always have a way of producing BTC and also it gives me diversity in options. By buying BTC you are limiting your options by a lot imo. Having a machine that produces BTC gives me the option to sell at any exchange rate (for example I can exchange my mined BTC at $400, $350, $300 etc and also at $500, $600, $700 etc), by buying and holding you are only limited to exchange only when the value goes up and even if you do you may exchange today at $1000 and in one week when the exchange is $1100 you won't have what to exchange. No matter the exchange rate after a while you will feel sorry that you turned your BTC to fiat because you could get a better rate. Also if BTC goes back to $100 or difficulty goes to the sky with a low exchange rate then I will just turn my miner off and turn it back on when it's profitable (exchange rate goes up or diff goes down). If you are holding to your 8.5 BTC and the exchange goes to $300 who do you think will suffer more? Me with the miner or you with the 8.5 BTC?
IMO all who throw as much btc for a miner and didn't calculated to return back the btc was.....
I think the most simple calculation (at least for me) if I spend btc to buy a miner in fiat I'll check with 55-60% increase per month in difficulty. If I see return and some profit on a miner I'll buy, if not, I'll wait.
Currently I'm in waiting status.... Only a better btc/usd could change this.
Edit: The famous sentence what I read on the forum and I think it's a good one: "You mine btc not fiat."
Edit2: At 800$ btc price this one would be the best deal. (Or S2)
I see a contradiction in your statement.
You will mine the same amount of BTC at $800 btc price or even less than what you are mining at this btc price because there will be more people who will start mining which equals to a higher rise in difficulty. Look what happened last autumn when BTC skyrocketed from $120 to $1200. Difficulty also skyrocketed (remember double the difficulty in just one month?) and we will have that kind of exponential rise if BTC price goes to the moon (and it will someday) and by the time everyone starts buying miners my farm will be much bigger and I will have more BTC mined than the ones who joined later.
Nobody is so good at exchanging their BTC at the right moment and while looking behind seems easy, doing it live much more rough. Mining for me is like a brake for greed and it keeps me from doing stupid and big mistakes.