I would continue to make small deposits of 50-100 until you are sure you have developed the discipline/skill to win consistently. There is no reason you shouldn't be able to win your way into a substantial bankroll. Plenty of us here have done it.

A lot of the bankroll suggestions I have seen are based on someone that is a winning poker player and has a finite amount of money they can ever devote to poker. I think the bankroll requirements some have suggested are ridiculous for the casual low stakes online player.

100 dollars is plenty to play $10 NL. If you bust, try again next month. 100 is also plenty to play .50/1.00 limit. Go bust? Try again later.

I think the 300 BB rules and other bankroll suggestions come into play more when you are planning on playing poker as your sole source of income and will not have the luxury of generating more money to play with.

When I first started, I started with $50. I never had to redeposit because I got lucky a lot early on. Later on I developed a little skill. If I would have gone bust, I would have either quit or put some more money in and tried again.

As long as you start with a good table stake at whatever session you decide to play, I wouldn't worry about your bankroll. Just sit at limits where you feel your skill and comfort level are right with a good stack and go for it.