Police were called to the man's Ann Arbor residence at 10:30 p.m. Wednesday for a report of a robbery, AnnArbor.com reported.
Ann Arbor police Lt. Renee Bush said the man and woman, a 19-year-old from Ohio whom he contacted online, agreed on a price for the woman's services, but when the man handed over the cash, the woman suddenly raised her price.
The man then called police.
"So she was arrested," Bush said.
Bush said the man and the woman's stories of the situation differed and that the man was not arrested, but it will ultimately be up to Washtenaw County prosecutors to determine charges in the case.
Police did not release any information regarding the price of the transaction, or the names of the people involved.