Tan, not sure about that cost figure, extract from the Airbus site for A340 has - "The four-engined A340 is free of the extra costs and complications which apply to all ETOPS flights for its two-engined competitor: extra equipment and maintenance, training and spares, a more stringent Minimum Equipment List and pre-flight check. To these must be added the risk of a commercially damaging diversion to an isolated airfield, with repairs and passenger assistance costing up to $1 million"
My italics.