Intuitively it should be 200bbs cause a lot more 3betting etc, but depends on the games... if you play against monster stations you can stick in a checkraise and win 300bbs with monster equity or have them drawing dead even. I didn't keep track of my sessions so can't give an exact answer. 50 buyins for anything bellow 1$/2$ is too nitty.

im playing blinds equal to $ 015/030, but i guess it plays alot higher since its 200bb buyins and pretty lose field. How many buyins do u think its needed for this levels then? pretty easy to drop 1000-1500 BB in a day here in this game..

Whatever makes you feel comfortable really, I play with 30 buyins now after having dealt with a lot of variance bad beats good runs and bad runs, but if you think in order to play your A game and not give a shit about going bananas in a deep pot with some straight blockers and backdoor nutflushdraw for example, go for 100 buyins even, no rule really. It is true that if you're very favorite in that game it's losing money on the long run to not move up, but it's more important to make a steady grind than be champ in a day or risk going broke.