Billionaire Donald Trump is self-financing his presidential campaign -- but he's not turning away donations. (Daniel Acker/Bloomberg)

This post has been updated.

Although Donald Trump boasts he is self-financing his presidential campaign, he hasn't turned away donations from supporters -- and those contributions added up to nearly $4 million in three months.

Between July 1 and Sept. 30, Trump's campaign says it received 73,942 unsolicited donations, pumping $3.8 million into his campaign coffers. The average contribution was about $50, and 71 percent of the money came from donors giving less than $200. Trump contributed $100,779 to his campaign during that time, although he adds that he has spent $1,909,576 of his own money since launching the campaign in June.

According to federal paperwork filed Thursday, Trump's campaign spent $4,035,076.35 between July 1 and Sept. 30. So far it has spent a total of $5,449,750. The campaign is spending money as quickly as it receives it, and the campaign reports having had $254,772 on hand as of Sept. 30.

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Trump likes to point out that he has spent far less than many of his Republican rivals yet still managed to dominate early polls for several months.

"While our original budget was substantially higher than the amount spent, good business practices and even better ideas and policy have made it unnecessary to have spent a larger sum," Trump said in a statement on Thursday evening. "To be number one in every poll, both state and national, and to have spent the least amount of dollars of any serious candidate is a testament to what I can do for America."

But Trump's paperwork reveals that he has constructed a massive network to support his campaign. The report lists more than 50 consulting firms or individuals being paid by the campaign -- nearly all of whom are labeled as being a consultant of some sort. He has hired an "event staging consulting" group and several individuals who provide "administrative consulting." Trump labels his lead spokeswoman, Hope Hicks, as providing “communications consulting.” Although Trump presents himself as an independent operator who comes up with his own policy ideas and doesn't pay attention to expert opinions, he has hired a number of strategy or policy consultants. Most of those working on the campaign are based in or near New York, the campaign’s home, or in one of the three early-voting states: Iowa, New Hampshire and South Carolina.

While other campaigns have been sinking money into television ads, direct mail and other traditional ways to reach voters, Trump's biggest expenses thus far appear to be the renting out large venues to host elaborate events that attract thousands and campaign swag. The campaign has thus far spent more than $800,000 on T-shirts, hats and other campaign-branded items.