Illinois (search) is about to start auctioning sentimental keepsakes — coveted license plates — that some state drivers say is a sad way to make money to close the state's budget gap.

According to this year's state budget, any license plate numbered one through 9,999 is to be made available to the highest bidder. Thousands of plates with single or small combinations of letters are also going on the auction block.

"Other states have done this and for certain, desired combinations — lettered combinations — have brought in very substantial revenues," said Illinois Budget Director John Filan.

The state hopes to raise $25 million toward narrowing its $5 billion budget gap. But the decision to auction license plates has dejected some car owners.

91-year-old Marge Marston and her 93-year-old husband Bill of Wenona have been married 70 years, and they have had the same license plate for an impressive length of time as well.

"We've had it for 40 years," Marge said. "Naturally, you grow attached to something you have had for 40 years."

Neighbor Pattie Ong said her number "105" plate is a cherished heirloom that dates back nearly as far as the invention of the automobile.

"We've had the plate since 1917. It went from my great-grandmother to Grandpa, and he had it for like 50, 60 years. So then it went to Dad," Ong said.

Filan said he understands the attachment, but the need to come up with cash trumps the emotional bond.

"I'm empathetic to tradition, but we do have a $5 billion deficit. These license plates are the property of the state," he said.

But some in state government say they doubt the auction will go as simply as some would hope.

"I suspect that we will be in court," said state Treasurer Judy Baar Topinka. "And it will be lawsuit after lawsuit after lawsuit for people who are going to want to keep their license plates."

The Marstons say they don't plan to sue for their plate, nor will they bid to keep it.

"We would never pay," Marge Marston said, adding that the digits don't have a financial value, but sentimentally the price will be difficult to swallow.

"As you get older, these things are more upsetting to you," she said.

Fox News’ Jeff Goldblatt contributed to this report.