Yes, it's unreasonable.

You won't always win, so don't expect to.

On prima for the year..my stats are a little over 12PTBB/100. This is a very high rate....honestly I'm not sure that I can even maintain that rate.

Anyway, it comes out to like $85 an hour. Even at $85 an hour it's going to take me 7 hours to make 3 buy ins on 1/2NL.

You also can't think of it as "winning 3 buyins a day". Somedays you might win 5...but other days you will lose 3 or 4. It just depends on the cards, your skill, and your discipline.

After being a pro for almost a year now...I can tell you that luck is a much bigger factor then I initally thought. Sometimes you just have to take beatings.

At the microlimits it's not unreasonable but at higher levels I don't think you can expect to consistently average 3 buy ins per day unless you're both very good and don't mind playing very long sessions. It's better to measure in Big Blinds per 100 hands though.