Keep in mind, giving away Power MINUS Lotus right now would be completely acceptable. Again, assuming High End Facebook.
Black Lotus: 4,800
Ancestral Recall: 2,000
Time Walk: 1,600
Mox Sapphire: 2,100
Mox Emerald: 1,700
Mox Jet: 1,700
Mox Ruby 1,600
Mox Pearl 1,600
Of this total, Black Lotus alone equates to 25% of that cost.
So, this is the difference between charging $100 for the event and giving away the full Power 9, or charging $75 Dollars and giving away all power EXCEPT lotus.
... Seems obvious to pay the extra 25 dollars and play for the lotus, right?
But this is also 189 players at $100 a piece TO BREAK EVEN, versus 141 players TO BREAK EVEN without the Lotus.
That's right, you require fourty eight extra players JUST to account for the Lotus.
Alternatively, you could give away the Lotus and a Mox for 1st and second, Library for 3rd and 4th, and Time Vaults for 5th, 6th, 7th, and 8th.
you're STILL looking at 11,000 dollars, needing 110 players to break even, of which 62! of them would be needed to just pay for the lotus.