In the era of Michael Bloomberg spending more than $100 million to win re-election as New York City mayor, it's worth noting that Donald Trump has spent just $47 million to essentially lock up the GOP presidential nomination, according to the latest Federal Election Commission fundraising reports though the end of March. (Trump loaned his campaign $36 million, per those same fundraising reports.)
By contrast, Ted Cruz's campaign spent $70 million, Hillary Clinton's has spent $158 million and Bernie Sanders' camp has spent $168 million.
What's more, Trump's campaign has spent just more than $18 million in advertisements - compared with the $77 million Jeb Bush's Right to Rise Super PAC spent alone, or Bernie Sanders' $56 million on ads, or Hillary Clinton's $43 million.
Of course, winning a party's presidential nomination on the cheap is one thing; winning a general - priced at $1 billion or more - is another.