Another way to calculate it in your head is to put a number to the # of times bob folds this as to the times that he calls. I say he's calling this about 1/3 of the time, which means he's dropping $1.33 to you every time you make this play, and to break even, needs to win that back when he calls in addition to the money he loses when you suck out (his EV for his calling range). If he doesn't make a profit, then you do.

The other big things that you need to watch out for are the blinds flat calling you with a monster (QQ+); you can lose a ton of money on rare occasions running into monsters here so be careful. Does anyone off the top of their head know what the chances are that one of two players will be dealt AA-QQ, AK? You gotta factor that in.