Fuel prices are high and expected to go higher in the future. The A330 simply uses a lot more fuel than the 767.
Let’s look at the numbers. According to the authoritative Airline Monitor (November 2010), the average 767-300ER in US airline service burns about 1,550 gallons per block hour (Boeing’s tanker uses a smaller airframe, but more equipment, so we don’t know it’s exact burn rate). The average A330 in US airline service (-200s and -300s; the FAA doesn’t break them out, but the KC-30 too would carry more equipment) burns about 1,900 gallons per block hour. If fuel is $50/bbl, that fuel burn difference isn’t the end of the world. If you start with a base year assumption of $100/bbl, and then add the usual US Government fuel cost inflation factor for a 30 year life span, multiply it times X hundreds of flight hours per year times 179 aircraft, you get a fuel-related operating cost difference wide enough to drive a truck through. The EADS up-front price discount would have been dwarfed by this huge fuel cost divergence.
RichardAboulafia.com