Then the owner of the store that sold Ertman the $1 Mega Millions ticket set him straight: It was worth not $150, but a cool quarter of a million.
"I didn't believe him - not at first," Ertman told The Bay City Times.
The 71-year-old laid-off factory worker bought the ticket in late December at the Bad Axe Party Store & BP Gas Station, and walked around with it for six days without realizing it was worth $250,000.
He must have written down the numbers wrong when he saw them on TV, he said.
Ertman was speechless when store owner Eli Kabban told him what he really had, and his wife, Rosalie "Penny" Ertman, broke down in tears of joy when she learned the news.
"We're the typical poor senior citizens, and our income from Social Security is not a lot," she said.
The Ertmans, who live in Sanilac County's Minden Township in Michigan's Thumb, said they spend about $7 per week on lottery tickets. They remained anonymous until Monday.
The couple are investing the money, and Donald Ertman also said he plans to buy his wife a new car and spend some of the money making home improvements.
And yes, they bought a few tickets for Tuesday's Mega Millions game, with an expected jackpot of $150 million.
"Now you see," Donald Ertman said, "that's worth a buck."
