Mining profit

[Phage]

I recently got interested in BitCoin mining. Now I am considering buying 2 graphic cards for my current rig and let it mine whole summer. The problem is that I constantly read here how mining becomes unprofiting in the future (eg. you make less than the electricity bills). However when I use this calculator, I see that if I buy two 6950s I will make 500-550$ a month. This means that I will pay off the cards in 1,5 month(s) (this is with the electricity bills included) and everything I make after that is going to be a pure profit. Is there something wrong with my calculations?

[Prze_koles]

Yea, difficulty is changing every 2016 blocks. And price is changing every minute

[bcpokey]

Read the like 4 threads on this topic on the first page of this forum.

Your calculations are flawed in that the price is highly unstable, the difficulty is highly unstable, and mining bitcoins itself is highly unstable (the amount varies by luck, even in big pools).

[Atroxes]

The short version:

The calculator calculates profits based on *this* moment in time.

More miners = higher difficulty over time.

Higher difficulty *can* mean higher valuation of Bitcoin, but it's not a certainty.

Santa could be real.

[Phage]

Alright, even if I make half the money, it's still around 250 bucks for just keeping my computer ON, right?

[Genrobo]

Alright, even if I make half the money, it's still around 250 bucks for just keeping my computer ON, right?

Essentially, you will be making BTC.
-cough-
No one mines for *bucks* around here.

[smell]

Check out http://bitcoinstuff.appspot.com/ for a calculator that takes difficulty into account...  disclaimer: i wrote it

[MCWey8]

I have read a lot and i feel it comes down to this,

mining is a hobby, it could be a loss, it could be a gain...

but you should only join to support Bitcoin not to make profit (since your probably wont), the people who have made big profits have been mining for AWHILE, have given back with charts of MH/s rates (lots of testing) , started a couple pools and spent a whole bunch of investment into hardware and electricity.

While it is VERY possible that you could come out ahead at the end of the summer, there are NO GUARANTEES and not even a percentage of success is available due to how fast Bitcoin price can change.

[smell]

While it is VERY possible that you could come out ahead at the end of the summer, there are NO GUARANTEES and not even a percentage of success is available due to how fast Bitcoin price can change.

I disagree.  Suppose you have a free PCIE and buy a 5830 for $100 (if you can find one), you start mining today at 300MH/s... by the 16th you should have 3.5 BTC which is worth about $100 right now.  You may argue that next week the market may crash.  Sure, let's suppose it does.  Suppose it crashes to US$10/BTC, well you've cash out for $35 and you return your GPU.  Now you're even or possibly up slightly...

[Littleshop]

Check out http://bitcoinstuff.appspot.com/ for a calculator that takes difficulty into account...  disclaimer: i wrote it

I like the calculator but wish it did not figure in the price increase in bitcoin the way it does.  Could it be an entry for a growth rate there as well? 

[smell]

I like the calculator but wish it did not figure in the price increase in bitcoin the way it does.  Could it be an entry for a growth rate there as well? 

Thanks for the suggestion.  I will add that later.  Did not want it to have too many options.  Probably will just go with a checkbox for either extrapolate price or not.  How's that sound?

[yyduinihao0]

Mining is still ok as long as you can earn more than the electric bill. The only problems is that you can not really predict the future difficulty growth and the price growth rate.