Total Cost of building PC: $1995.94
How many bitcoins can I buy with $2000? As of this writing it is about $0.066 per bitcoin. So I could buy 30,303 bitcoins if I had $2000 laying around.
Now, how long would it take for my newly designed 25,000 hashes-per-second machine to generate 30,303 bitcoins? Using the bitcoin generation calculator available athttp://www.alloscomp.com/bitcoin/calculator.php, on average it will take 1 day, 19 hours, and 44 minutes to generate 50 bitcoins. After doing a little arithmetic that means it will take a little over two years to generate 30,303 bitcoins!!! Let's not forget to mention that the difficulty levels seems to be rising over time so it could take much longer than that. In addition, the electricity costs to run a server could add up.
That was in August. Now?
For $2000, at current rate, you will get 8000 bitcoins.
To generate 8000 bitcoins, at current rate (50 coins/24 days) it will take 3840 days! Almost 11 years. However, current rate will change, resulting in significantly more time.