 A new state prison for men in Concord could cost up to $500 million. The plan is to build on state-owned land behind the existing prison. Corrections Commissioner Helen Hanks told the Executive Council yesterday the state is spending $10 million on plans for the new prison to replace the current facility, which was built in 1812. She said the woman's prison opened in 2018. It's smaller and had a lower price tag because building costs were less at the time.