You can do your own simulations with SwongSim, explanations how it works are somewhere in this board, it's simple, free and a great software. It's way better to understand why you want a Bankroll of whatever size than just blindly following some "u need at least x BI".
FWIW 1$ games should be so soft that if u have a basic grasp of poker, 100 BI is a way too conversative approach and losing value thru not moving up early enough