The current cash value of the MM jackpot is $44.9M. The advertised annuity jackpot is $77M meaning the cash/annuity ratio is 0.599.
The current cash prize in powerball is $14.6M which is advertised as $30M annuity, meaning the cash/annuity ration is 0.489
This means that a cash value prize (which represents the true value of a lottery prize) equivalent to the current MM jackpot prize would be represented as a $93M jackpot.
The entire annuity business (as well as ever lengthening odds) is misleading, of course, but most people are aware of it. Still, many people, myself included, use the advertised jackpot as a shorthand. I don't doubt that MM will aspire to be as misleading as PB in the future, but it is always a good idea to keep in mind that the real prize of the two lotteries are very different. In fact, the recent $340M advertised jackpot for PB was actually smaller than the recent $315M MM jackpot.
When I decide how many tickets to buy, or whether to buy tickets at all, I look at the expectation value, which is a function of the size of the prizes that are possible to win (cash pretax value) divided by the odds of winning. Expectation values for the two lotteries right now are 0.43 for MM, and 0.32 for powerball. Powerball does somewhat better in expectation value since the odds against winning are lower. Still, neither lottery gives an expectation value close to 1.00 until they are near record size. An expectation value of 1.00 or greater (which has only happened a few times, even at pretax cash value) is when a game is considered a "good bet."
Like most lottery players, I don't insist on a "good bet." The better the bet is however, the more likely I am to play.