Quote from: bomberb17 on November 20, 2015, 09:41:51 AM

There is no point to buy mining hardware and just hope for a BTC price increase. Just buying and holding BTC is much simpler and safer. In other words, you should calculate your initial costs in BTC and see how many BTC you will get back. By investing 4.73 BTCfor a S7 + 0.487 BTC for PSU + ~1BTC for customs fees = 6.217BTC total, you will probably earn these BTC back by August 2016, just after the halving.

Why the "blanket" statement? It may not be profitable for "you." Does this mean it's not profitable for anyone else? Like in another country, maybe? I can tell by your local time and your estimated cost for customs fees that you are located in Europe.

1 BTC for "customs fees?" Really? WOW!!! No wonder you don't want to buy S7's. I can imagine your power costs may be substantially more than many of us in the US as well.

By the way, I also have my own PSU's for over a year from mining with previous rigs I owned well before the S7 was available. They were $65.00 USD each [With free shipping] and two of them can power 5 x S7's very easily. Do I have to buy new PSU's? No, I don't. I will have to buy more PCI-e cables to power them @ $3.25 each. That is 7 x 16 AWG PCI-e cables for each S7 = $22.75 USD (0.07 BTC).

I have enough PSU's at present to power 54 x S7's. Will I need to buy more PSU's soon? Yes, I will. Even if I do have to buy more PSU's with breakout boards soon, I can get them at $65 USD + $65 for breakout board = $130 USD (0.39BTC) for each . Don't forget that each PSU I use can power 2.5 x S7's. So, if we divide 0.39BTC by 2.5 = 0.156BTC costs for PSU for each S7. 0.156BTC + 0.07BTC for PCI-e cords = 0.226BTC

So, 0.226BTC my costs for PSU to power 1 x S7 compared to your 0.487BTC for PSU with PCI'e cords is more than double my cost.

I have no "customs" fees. I have the occasional brokerage fee of $29.00 USD to $69.00 USD depending on how many units were purchased. Many times there is no brokerage fee at all. It depends on whether I'm one of the lucky ones to be chosen among all the packages coming through.

So, try 4.73BTC for S7 + 0.226BTC for PSU with breakout board and PCI-e cords = 4.956BTC + 0.155 for shipping = 5.111BTC for me in the US compared to your 6.217BTC in Europe.

But remember, the first 54 x S7's I purchase do not include the additional costs of PSU with breakout board and PCI-e cords. Which means the first 54 x S7's for me would be 4.73BTC + 0.155BTC for shipping = 4.928BTC for me compared to your 6.217BTC.

Quote from: bomberb17 on November 20, 2015, 09:41:51 AM

First of all, these increases are monthly increases, not the increase every 2 weeks.
Second, I assumed 5 billion increase each month, not 5% (i.e. linear increase, not exponential).
These assumptions for difficulty increase are fairly optimistic.
Even with ZERO diff increase. ROI will happen in June 2016.
And remember, these calculations are with FREE electricity!

Yes, I know your calculations are with FREE electricity. However, the cost per S7 for me is 1.106BTC cheaper than yours IF I had to buy PSU's with PCI-e cords and breakout board. My costs for the first 54 x S7's are 0.226BTC cheaper than that, seeing that no PSU's are required. Which means 1.332BTC cheaper than your costs for the first 54 x S7's.

Quote from: bomberb17 on November 20, 2015, 09:41:51 AM

All ROI calculations should assume a stable BTC price.

Oh really? So, it's okay for you to "buy" your BTC and speculate on price? Yet, we who mine BTC, cannot speculate the price of bitcoin will increase just as you speculate? We who mine have to assume a stable price (flat line)? If that's the case, "you" who "buys" BTC has to assume a "stable" price as well and thereby not make one cent in profit cause you too would have to assume a "flat line price with no increase." Why is it that we (who mine) cannot speculate on our investment and you (who buys) can speculate on yours?

The rules you have placed on miners are disingenuous. Both buyers and miners can speculate on price when investing. We are simply investing in a different "means" to accomplish a similar "ends" ... RETURN ON INVESTMENT WITH PROFITS.

We (who mine) are "buying" BTC just as you are buying BTC but in a different way. You (the buyer) and we (the miner) can BOTH SPECULATE on an increase in price of BTC. I'm speculating the price of BTC will increase at a percentage rate much higher than the percentage rate of difficulty increase over the next 9 months. Just as you (the buyer) speculate on the price of bitcoin as well with Elliot Waves, bullish or bearish news or by whatever means you use in your speculation to have not only a return on investment (ROI) but gains to boot.

Is my speculation a bit more riskier than yours? Yes. However, where there are greater risks can also result in greater rewards if speculation for those greater risks come to pass.