BJ21.com Free Message Board
I am not at my computer with BJRM, so I can't give you an exact answer, but I would guess that your risk of ruin with a $500 bankroll is extremely high. You could probably get an exact answer to your question if you included one more piece of information: what is the penetration in the game you describe?
Otherwise, you are taking a strong approach to what is essentially a lousy game. I'm not especially familiar with the alpha count you use, but I am assuming that a plus 3 count indicates a good player advantage. You may want to consider incorporating Kelly-style betting when you make your bets. BJRM would be a very good tool for this.
Good luck in your pursuit and you may want to think about looking for a better game, if one is available near you.
BJ21.com Free Message Board is maintained by Pi Yee Press