Welcome to the forum.

I'll take a stab at your question, though I am far from a pro. Let me direct you to 'rillas excelent post on bankroll management here. In it he recommends 12 to 16 buyins for NL tables. I think that works well for SnG's also, but perhaps you might want to get it up to 20 to be extra safe. So it looks like you are about ready to move up.