Live tournaments presumably dont run all that often, so depending on your personal situation maybe its completely fine to not have a bankroll but simply pay the buyins from your paychecks. After all spending 150$ on an evening in the casino is not really that different from spending 150$ on eating at a nice restaurant with your spouse, and if you happen to score, its just an unexpected bonus.
Online you can play several tournaments per day, so there it makes a lot more sense to give yourself a bankroll and try to manage this in a responsible way. As others have said 100-200 times the tournament fee is pretty standard for MTT players.
__________________
|