An overall $9 billion cost estimate is more honest than relying on individual plane costs, says the minister handling the purchase of Canada's new fighter jets.

Despite a promise by manufacturer Lockheed Martin that Canada will get its F-35 fighter jets at a cost of $65 million each, Julian Fantino, Associate Minister of National Defence, says the government's overall $9 billion estimate is the more honest number.

The cost of the F-35 depends on the number of planes ordered by other countries, as well as on how early Canada wants to get its order. The manufacturing cost goes down as more planes come off the assembly line, with Canada expecting the U.S. to absorb the bulk of the F-35's development costs.

"There are just so many variables, and that’s why I think the more honest, ethical response to all these issues is the $9 billion figure, which in fact will be the ceiling that Canada will be investing in these particular aircraft," Fantino told Evan Solomon, host of CBC's Power & Politics.

"We can have this debate up, down and sideways, but the reality is that we are trying to do the best we can, being very responsible with taxpayer dollars."

Canada has ordered 65 fighter jets. The $9 billion total cost estimate breaks down to more than $138 million per plane.

The $9 billion estimate includes training and maintenance costs.

A number of experts have disputed the cost of the planes, including Parliamentary Budget Officer Kevin Page and former defence officials. An American procurement expert from the U.S. General Accountability Office estimated the F-35 A, the model Canada is buying, would cost between $100 to $115 million each.