I've never tried to win like that in one play because mostly I won 200 dollars I think in one play but the total of the bitcoin which is 0.3 is thousands of dollars cost. I hope when I tried to play also dice game I will win more than that. Other people win more than 1 bitcoin. Maybe they have big capital for that and they are lucky on that day but maybe once you are unlucky you will lose it also.
You may not know that quiet gamblers on BitDice has large bankroll so they can keep on going. It's not just about luck but it's also about on how much they are willing to lose, how much they are willing to risk.
Luck comes in unexpected days so combining having good amount of capital with luck, you'll really going to have the nicest day. But this doesn't happen usually for everyone, have a try to dice with BitDice folks.