Michael Bloomberg's short presidential campaign was pricey to say the least. According to a Federal Election Commission filing, the former New York City mayor poured $1.05 billion into a campaign that lasted just over three months and employed 2,400 staff, some of whom are now suing. That sum is more than the total spent by all other Democratic contenders since January 2019, based on current numbers, ABC News reports. Bloomberg, who left the race March 4, reported spending $158 million that month. In total, he spent about $18 million for each of 55 delegates won, including $453 million on television ads and $82 million on digital ads, reports NBC News. (More Michael Bloomberg stories.)