The man was attempting to sell fish to the elderly woman on Rectory Road, Church Warsop.
He was invited into the house to take an order, but returned with a larger quantity than the victim requested.
The victim then handed over £100 and the man was left alone for around two minutes, while the victim fetched the rest of the money.
The victim then handed over a larger quantity of money than what was agreed by mistake, but wasn't given the money back.
The suspect then left the house, where the victim noticed a further £250 had been stolen from a handbag.
The incident happened at around 10.30am on October 24.
The 49-year-old man has been arrested on suspicion of burglary and remains in police custody. The arrest followed a witness appeal issued by police.
Detective Constable Caroline Bailey said: "The public's help is vital in helping us to prevent crime and bring offenders to justice.
"It's thanks to the people who called us, after seeing our witness appeal on Facebook, that we were able to make this arrest.
"One person managed to take down the full registration number of a van connected with the incident and another person rang in giving us a really good description of the offender.
"We've taken statements from these people and I'd like to thank them for coming forward with their information and for their cooperation during our investigation."