Of course the DAA can point to Aer Rianta as the authority who sanctioned the project. The DAA only came into existence some months after the contract was signed.
Of course the project would have cost a lot less if Cork hadn't been starved of infrastructural investment for decades. Roads, drainage, lighting. car parking etc all had to be upgraded so it wasn't simply a question of building a new terminal.
Furthermore massive excavation work had to be undertaken due to the location chosen for the airport in the 1950's.
Maybe someone should access the Department of Transport files from that era concerning that decsion.