Montana Powerball Website (same game as Powerball played in other states)

Using the same logic followed on the Montana Cash Page, and using the odds printed on the back of the Powerball playslip.
There are 120,526,770 combinations of numbers. at $1 each it would cost $120,526,770 to buy them all.
If you bought all combinations, you would win:
The Jackpot, (5 of 5 picks + the powerball)
(42) $100,000 prizes, = $4,200,000 (5 of 5 no powerball)
(240) $5000 prizes, = $1,200,000 (4 of 5 + the powerball)
(9840) $100 prizes = $984,000 (4 of 5 no powerball)
(11,280) $100 prizes = $1,128,000 (3 of 5 + powerball)
(461,788) $7 prizes = $3,232,516 (3 of 5 no powerball)
(172,922) $7 prizes = $1,210,454 (2 of 5 + powerball)
(971,990) $4 prizes = $3,887,960 (1 of 5 + powerball)
(1,721,811) $3 prizes = $5,165,433 (0 of 5 + powerball)

The take would be $21,008,363 + the jackpot.

of course there would be tax on a $100,000 prize or a $5,000 prize or the jackpot, even if you wone just that one prize. To figgure the break even point you need to take this into account.
$4,200,000 *.6 = $2,520,000 (for the $100,000 prizes)
$1,200,000 * .6 = $720,000 (for the $5,000 prizes)

The real take would be $18,848,363 + the jackpot

$120,526,770 cost - $18,848,363 = $101,648,407 Cash needed to make the jackpot even money. The advertised jackpot is about half what the real jackpot is in today's dollars due to the advertised ammount being an annuity. so, $101,648,407 * 2 = $203,356,814 needed jackpot, but you don't get to keep it all. The jackpot must be adjusted for the IRS $203,356,814/ .6 = $338,928,023 is the minimum advertised ammount where the lottery is a "Fair" bet.

You will still run the risk of having to share the jackpot with others if there is more than one winner, but every ticket sold adds to the jackpot, and their chance of winning sucks just as much as yours does. That and I don't know how to account for the other players effecting this accounting means, I'm not going to worry about it.