On a typical morning, customers trickle in to the Oaks Service Shell station on King Street in Charleston for gas and cigarettes. On Tuesday morning, a line of 15 faced cashier Bobbie Gathers by 9 a.m.

She knew what they wanted.

"They look at that jackpot, they see $250 million, and they say, 'Let's go for it,' " Gathers said. "It's crazy."

What Gathers calls crazy, South Carolina's lottery officials call a "high jackpot run" -- their term for when the Powerball jackpot reaches epic heights and ticket sales start to follow. After Saturday's drawing failed to turn up a winner, the prize money grew by $50 million. Some local ticket sellers say sales have doubled. The next drawing is tonight at 10:59.

Predicting the timing of a lottery frenzy is an imperfect science, but state officials and local ticket sellers all put the threshold at around a $100 million prize.

"That's when we really start seeing an increase in ticket sales," said Tara Robertson, spokeswoman for the South Carolina Education Lottery.

But Robertson said she didn't know why so many South Carolinians waited for a nine-digit pot before getting in the game.

"I suppose to some people (it's) nothing," she said, "but $10 million is a significant amount of money for our player base."

If tonight's drawing lands a winner, he or she will have the option of receiving the $250 million over 30 years or walking away with a $141 million cash prize -- $93 million after taxes.

The Powerball record is $315 million, a prize won last winter by Jack Whittaker, a construction contractor from West Virginia. Whittaker chose to take a lump sum payment, ending up with $111 million after taxes.

Powerball's super-sized jackpots are made possible by super-sized player pools. South Carolina is one of 24 states, the only one in the Southeast, that participate in Powerball.

Last month, 43 million Powerball tickets were sold in South Carolina. Robertson said the monthly average is about 30 million.

Per capita lottery spending in South Carolina at about $80 a year is below average among the 38 states with lotteries, according to a recent CNN survey. The list is topped by Rhode Island, where spending is about $1,115 per capita, followed by Delaware, South Dakota and Massachusetts. South Carolina ranks 29th in per capita spending, while residents of Arizona, Nebraska and Montana spend the least per person.

Some Charleston-area players said they just don't get interested in the game until the jackpot nears the $100 million mark because they're only in it for the fun.

"The more money, the more excitement," said Donna Campbell, a restaurant manager from North Charleston. "My sister saw the $250 million and said, 'Oh, I'm going to play now. Now it's exciting.'"

Campbell, who has been spending $15 a day on lottery tickets since July 1, said she plays for the money. "I'm a lucky person. I think I'm going to win."

Dave Brooks was more philosophical about his chances. "I play because I can't win unless I play. You got to be in it to win it."