Story highlights "I make $400 million a year, so what difference does it make?" Trump asked

Trump also said he had just put out a position paper on immigration

Des Moines, Iowa (CNN) Donald Trump said Saturday that he's prepared to spend $1 billion on his campaign if necessary.

"It's irrelevant," he said when asked by CNN's Jeremy Diamond outside the Iowa State Fair on how much he has spent so far on his campaign. "I make $400 million a year, so what difference does it make? What I want to do is make the country great."

Pressed again later in the afternoon if he would spend up to $1 billion, Trump was more definitive: "If necessary, I will spend it, yes."

Trump said he does not have to worry about pleasing lobbyists like other candidates because his race is self-funded. The businessman said he recently turned down $5 million from a lobbyist wanting to contribute to his campaign.

The bombastic billionaire, who has claimed he's worth $10 billion, has given to candidates in the past -- including Democratic front-runner Hillary Clinton -- so, according to him, they will do his bidding.

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