I did A LOT of hours per day to be completely honest. Sickest month I have ever had though.
High amount of hours per day but mainly because of lack of action and 1-tabling. At $30s with action any time of day and just 2-tabling (can be more) you're looking at roughly a 9-5 job in terms of hours put in. Assuming 12 games per hour that is.
And 5% roi for someone from $300s who moves down to $30s is just a wild guess. Sharky is probably down to those stakes, so the person attempting this would mostly play weaker regs. Ego and fancyplay syndrome will be huge to exploit, especially if he has a list of regs to pick from.