The cost of devolution for Peterborough and Cambridgeshire will be £1.7 million in the first year.
Newly released figures show that a combined authority for the county will cost £674,000 to run, with a cost of £146,000 to set up.
An election for a mayor would also cost £756,000, and the mayor’s office would cost £135,000 in the first year.
Councils will decide next week whether to sign up for devolution, with Peterborough City Council the last to decide on Thursday evening at the Town Hall.
However, businesses have already given their approval to the controversial deal.
In a unanimous decision last week, the board of the Greater Cambridge Greater Peterborough Local Enterprise Partnership (LEP) voted in favour of the proposals.
The LEP is now the first organisation which would be part of the new combined authority to fully back the plans.
Its chairman Mark Reeve said: “With a strong partnership between the public and private sector, we are well placed to take advantage of the opportunities that devolution brings both in this first deal and future deals.”
The devolution deal will create a new £20 million annual fund for Peterborough and Cambridgeshire for the next 30 years to support economic growth and £100 million for housing. Peterborough has also been promised its own university if it signs up to the combined authority.
However, there are concerns in the city over the power of an elected mayor, a loss of sovereignty for the city council, and that Cambridge will benefit much more than Peterborough.
Councillor Robin Howe, speaking on behalf of all council leaders in the county, said the Government will pay for the combined authority’s running costs. He added: “Overall, for each £1 spent to run the mayoral combined authority for the next five years, it will generate funding of at least £45 to be invested in Cambridgeshire and Peterborough.
“This deal will create new opportunities for our residents, help to attract new business and produce substantial economic growth.”