I though 30 buy-ins were too conservative for bankroll. And I was wrong.
A clear proof that losing 20+ rounds straight in poker is not impossible now. On one particular occasion, slow playing a full house got cracked by a straight flush. And top set on flop was undermined by a gut-shot straight draw. So 2-hour of gaming leads to an almost 30 buy-ins drop.
End of beat. Guess MTT is more for me.