Thanks, after reading this thread fully I am now undecided.
Am I corect in thinking the mod miner quad will generate at current difficulty about .5 BTC per day.
This will take about 220 days to break even if nothing changes but the block rate will halve soon too.
Although if the BTC/USD keeps going up then I wouldnt need as many coins to get back my investment.
I am not thinking of this as a get rich scheme in any way shape or form and do not expect to get back my investment fast however a modest 25% profit in a year would make this worth my while.
Is this possible? If I bought one of these units now for $1100 will it be able to generate $1375 worth of coins before the end of Sept 2013?
It is all uncertain. Nobody can tell you for sure, because there are too many variables and many of them are interconnected. It also depends on your world view which is subjectiv. This is my bet:
Difficulty will not decrease significantly unless something bad happens, and then we're all f*cked. It will increase >10 times if the ASICs are coming and they will, but it is uncertain when exactly.
Block reward is going to halve in December. This should already be included in the current price, but maybe it is underestimated and price will go up because the demand grows faster than the number of Bitcoins.
Economic crisis and bad decisions by politicians will cause American and European currency to keep loosing their value in the years to come. Bitcoins will then be worth more in terms of USD and EUR.
If ASIC miners are coming any time soon and the price of Bitcoin does not increases significantly, you will not earn your investment back.
There are a lot of if's and you have to make up your own mind. It also depends on how much you can afford to loose. If you cannot miss your investment, do not do it. Otherwise I would say: go for it and even if you loose money you will have learned a lot. As a fellow miner I would say: don't do it, it leaves more Bitcoins for me :-)
All this and...
... there's still money to be made with high end GPUs, especially if you have cheap electricity. 7970s will be resellable, even if everyone sells them at once. Anything lower than that will probably hurt a bit if/when the selling rush starts. Can't say that about FPGAs however.
Also, mining for me was profitable after electricity when BTC was $5/coin. It's now $11 a coin and isn't showing any sign of decreasing. Most politicians in the US and EU are bought and paid for, which means the idiotic decisions will continue until morality improves on this planet, as current government is structured to attract greedy selfish "available to the highest bidder" control freaks.
That means if ASIC is delayed, even when the great halving occurs, it'll still be profitable for me. That and it'll be winter on my side of the planet, so I won't have cooling costs anymore, and I should have less heating costs.
So, for now, it looks to me like I'll be hanging tight with my 7970s until ASIC kicks in. At that point I'll liquidate my 7970s and use the money to join the ASIC bandwagon.
M
