You would have to make at least $100 of bets from the deposit.
It's a standard 1x rollover on all deposits if you don't take the bonus.
So, you win $250 from the $50. You deposit $100.. Your balance is $350 and you have to make $100 worth of bets and then you are good to go
So in fact your would have to make 7x your bet in order to cashout. Don't you think it's a bit unfair that you have to wager the whole of the deposit at least once to withdraw ?