re: Poker & How to build a bank roll
Until you get to s significantly higher level, one where the money is meaningful, focus on your game, not your roll. If you're okay adding $20 from every paycheck, fine. Do it.
BUT... understand that the purpose of adding to your roll isn't to move up. It's mainly to have enough BR to move up when your game is ready. In addition, it gives you some flexibility to take shots in order to help gauge your readiness. For instance, let's say you feel you're improving and decide to take a 5 buyin / $20 shot at NL4. If your roll is say $60, you may want to wait until you've built it up to $80 since you do have to be prepared to lose the entire $20. But if it's $160 because you've added $20 a few times, you have much less concern about grinding out money to fund your shot.
there are two requirements to move up in stakes, enough BR and enough game. You can successfully move up with a small BR (trying to do this isn't recommended though) if you have enough game, but a large BR won't save you if you don't have enough game.