It's a tough question to answer. Honestly, depositing small means you are under rolled and will likely go break. My only fear is that a bigger deposit could lead to greater loss if you aren't ready. If you believe that you can stick to a conservative BRM strategy then I recommend a very large deposit. I also recommend trying to find a substantial rakeback bonus to accompany the deposit. If you want to play 10nl, deposit 500$. 25nl 1k. Once your comfortable with online you could conceivably beat 10nl with 200$ and 25nl with 400$ but its dangerous, even if you are a spotless player variance is still a factor. You will be at a disadvantage because your opponents have played online more than you. My conclusion would be to deposit bigger, but make sure your ready both technically and mentally. You need to be able to break even at least, and avoid megatilt.