Donald Trump has loaned his presidential campaign nearly $25 million so far, a sum that far exceeds what I might be able to loan to a campaign of my own, were I foolish enough to ever run for office. I'd venture to guess that it is also more than you might be able to casually spend on a campaign, though I don't mean to jump to conclusions. Apparently there are 142,000 households in America worth $25 million or more; if you live in one and are reading this: Hello!

For Trump, that $25 million is theoretically 0.3 percent of his $10 billion net work. Or, if you prefer more objective assessments of Trump's worth, 0.8 percent of Trump's $2.9 billion, as calculated by Bloomberg. Much of that is tied up in real estate, of course, and since Trump hasn't yet sold Trump Tower to be able to pay anyone's legal fees, we assume he's got more petty cash where that came from.

So not a lot of money to Trump; a lot to (most of) us. But in terms of how much past candidates have spent on their campaigns, it's also a relatively small amount.

Pulling data from RealClearPolitics, the Center for Responsive Politics and contemporaneous news reports, we put together this list of candidates who'd spent $10 million or more on their candidacies. We've included an adjustment into 2015 dollars, but in many of the cases, they outspent Trump anyway.

There's Meg Whitman, who spent $140 million. Steve Forbes, who laid out $38 million. Arianna Huffington's ex-husband, Michael, who spent more running for the Senate from California in 1994 than Trump has spent this year. And then there's Michael Bloomberg, one-time possible 2016 spoiler, who spent $310 million combined, in 2015 dollars, on his three New York City mayoral bids. It makes Trump's spending look like chump change.

What's more, Trump's spending is a loan from him to the campaign. He can be repaid for his investment -- plus interest. Meaning that the extent to which he's self-funding over the long-term is subject to later revision.

We'll also note that more than a quarter of what Trump has raised has come from individual donors. Some of that money is from people who bought Trump hats and other schwag. Some is people writing checks.

It's often the case that self-funders give the bulk of their campaign's total money. That's not the strategy that Trump is pursuing.

Again: $25 million is a lot of money by non-Trump standards. And most of Trump's campaign resources come from Trump himself. If anything, the fact that he's managed to invest only $25 million so far should be a point of pride for the real estate magnate: Clearly Donald Trump made a great deal with the Donald Trump campaign.