CHICAGO (CBS) — The Mega Millions drawing coming Friday night is the biggest lottery jackpot ever, in the entire world, and you still have a shot at winning it.

As CBS 2’s Susanna Song reports, the jackpot now stands at $640 million – up $100 million from yesterday alone. People were stopping at their local 7-Eleven stores all night long, and CBS 2 found one person spent $105 on tickets.

The one-time cash payout before taxes: $462 million.

LISTEN: WBBM Newsradio’s Dave Berner reports

When the tickets print, the dreams get big.

“My husband can retire. We have five kids. We could get a better van,” one woman said.

At one 7-Eleven in Oak Park, someone already won a second place Mega Millions prize of $250,000.

“This is a lucky store,” one of the men behind the counter said.

Customers were also snapping up tickets at the 7-Eleven at 1109 Maple Ave. in Lisle.

“They’re going high; people are buying. They’re trying their luck. They want to win,” said the owner of the store. “Selling more tickets than everything.”

But luck is all it’s going to be. We all must remember that mathematically, this isn’t like going to the slot machine.

“The chances are still very, very low,” said Roosevelt University math professor Barbara Gonzalez. She said if you want a 50-50 chance at winning, you would have to buy “87 million tickets. I don’t think you can do that.”

Illinois Lottery Supt. Michael Jones told CBS 2’s Kristyn Hartman that on Thursday, tickets sales were “averaging $500,000 – a half billion dollars an hour.”

And as we get closer to the 10 p.m. hour, ticket sales are sure to speed up.

Financial experts have some advice if you’re lucky enough to win. Financial analyst Terry Savage recommends a lawyer, as well as tax and financial planning professionals to establish a trust structure.

“Where you can hide behind the shield of this organization and say, ‘I’m sorry, my financial planners only allow me to distribute X each year, and I’ve come to my limit,’ ” she explains.

Savage says do that before claiming your winnings or before telling anyone.

And on the subject of telling anyone — don’t.

“If you can, stay anonymous,” she says. “You’re not required to come forward although it’s a thrilling moment, I’m sure. But having that much money can really ruin lives.”

Lump sum or annual payout?

Savage says here’s where your tax planners come in handy.

“If you take it now in a lump sum, just figure about half will go to the government in taxes,” she says. “If you decide to take it out over the years, you suddenly are part of that one percent that has to worry about future tax rates, and remember back in the 60s, the top personal tax rate was over 90 percent.”

With all of that practicality out of the way, Savage says, yes, you can splurge on the dream house or vacation.

“You won the lottery, there’s no reason you can’t treat yourself to some of your fondest dreams, but you’d be amazed at how fast that money can go once you start handing it out to all your relatives and everyone who comes with a sad story.”