Just for fun while waiting for Avalon to get around to shipping B3 units, I created a google spreadsheet to project the estimated BTC generated for a given hashrate received at a particular time during the year. Is it pretty easy to use... just put in your expected delivery date in the yellow box, and your hash rate in the green one. Feel free to try it out!
https://docs.google.com/spreadsheet/ccc?key=0Auya3iRE6az1dG9fRkpXdFJtT1dNX0VCU1F0VFFUX3c&usp=sharingTo get the projected hashrate I used historical some data points starting in mid January through this last for difficulty adjustment (6/16/2013) and used and exponential fit in wolfram alpha.
...
One caveat:
Wolfram alpha's best exponential curve seemed a bit optimistic on growth rate. I upped it a bit to what I think would be more conservative (but who knows?!).
These projections put the difficulty at 100M+ at the end of september, and 1B+ at the beginning of March 2014.
I am not sure how to allow you guys to make your own edits without saving... so if you want to edit, you will have to make a copy I'm afraid.
It is impossible to get an accurate prediction with just extrapolation. There are 4 more pieces of information you could add to make the predictions much more accurate:
1. How much hashing power is expected to ship over the next year or so (and when).
2. The difficulty rate of change at which an ASIC costs more than the amount it will ever mine.
3. The difficulty at which electricity costs make it unprofitable to mine with an ASIC.
4. The difficulty at which electricity costs make it unprofitable to mine with an GPU.
