One thing I noticed while playing around with the calculator -

I entered an initial scenario of a coinflip between the blinds on the very first hand of a Double or Nothing SnG, and found that, assuming a $50 prize pool ($5 entry), a flipper would lose $1.89 on average - quite a bit!

I then entered the same scenario, but changed the payout structure to a standard 10-man $5 SnG - 25/15/10 - and found that, while it is still a losing situation (about $0.49), it is not nearly as bad.

Conclusion: As the payout for first place goes up in relation to the rest of the field, the lesser the strength of your hand must be in order to justify an early gamble.  While some players may take this to mean you should take early gambles in large scale MTTs (such as the Sunday Million), the exact opposite is true - in fact, it's even worse of a move compared to the DoN SnG.

In a DoN SnG, 1st place pays out 20% of the prize pool - in this week's Sunday Million, 1st place only got 14.71% of the prize pool.  Instead, you should be looking at small SnGs where 1st place gets a much larger piece of the pot (although, in small SnGs skill plays a much larger factor in deciding the winner so if you need to rely on luck, you may wanna stay away altogether).