I haven't played much poker in these days due to some RL works I wanted to finish. However I am tempted to plan my poker career so I looked at the stats on my Poker Tracker.
For $12/180, I have the following stats and calculations:
* Total 2,133 games played
* Mean = $6.967 or 58.06% ROI
* Standard deviation = $85.644 or 7.14 buy-ins
* For 95% range, my true mean will be between $3.33 - $10.60, or 27.77% - 88.35% ROI
I didn't know the possible range is still that big and I have 2.5% chance that I have below 28% true ROI. If unluckily I have only about 30% true ROI, I would be pissed.
If I am going to play 1,000 games per month, I will expect to win $6,967, with the mean in the range of $3,330 and $10,600.
If I am going to play 1,500 games per month, I will expect to win $10,450, with the mean in the range of $4,995 and $15,900.