Warren Denholm's Ardmore aircraft workshop caters to the world's richest desires.
"It's always a struggle to make it look like it's a good place to spend millions of dollars," Mr Denholm joked of his business south of Auckland.
However, the most discerning of business tycoons and aviation buffs are shelling out millions for him to build the best private aircraft money can buy.
"We have two [billionaires on our books] at the moment … we are only a little outfit so we couldn't have too many at once," he smiled.
Texan oil mogul Rod Lewis is one of them, and wants Mr Denholm's business to build him a version of the iconic World War II Mosquito aircraft to join his war bird collection in San Antonio.
"[They're] probably better than when they were originally built," Mr Lewis told Seven Sharp.
Mr Denholm said a job the size of the Mosquito project would be "as expensive as people would ever expect to pay".
"You wouldn't get much change out of $8 million."
His Avspecs team created history four years ago with the completion of the world's only airworthy Mosquito.
"He's got an excellent reputation, everyone knows an aircraft built by Warren is going to be a top notch aircraft," Mr Lewis said.