You can fairly easily figure out the expected value of a ticket at any given point based on the jackpot and the number of tickets in play for a particular drawing. But even if it comes out to more than a dollar, the variance is way to high to make it attractive to most people who've thought it through. You can reduce the variance (maintaining the same expected value) by buying a large amount of tickets, especially with a group, but you're still not going to get it down to the level of almost any other non-lottery gambling opportunity.