How much is Donald Trump's travel and protection costing?

President Donald Trump's 2018 budget proposal is unabashed in its goal: slashing or eradicating a number of social and research programs to offset new spending on defense and homeland security. That emphasis quickly met with broad criticism, including from some who pointed out an apparent contradiction.

Trump places a heavy emphasis on cutting waste and targets for elimination programs that, in some cases, cost the government only a few million dollars a year. That is a lot of money in the context of the amount of money you or I spend in a year, but in the context of the government, spending a million dollars is like someone with a US$50,000-a-year salary spending one penny.

What really jumped out at some people, though, was that Trump was proposing cuts to some relatively low-cost programs shortly before he prepared to fly to his Mar-a-Lago resort in Florida. According to an analysis from Politico, that's a trip that costs about US$3 million ($4.3m) each time - and it's a trip that he's made three times this year.

If that US$3m ($4.3m) estimate is true, he could have funded the U.S. Interagency Council on Homelessness - budgeted at US$4m ($5.7m) in 2016 - for three years if he'd just stayed in the White House.

Others noted the cost of protecting first lady Melania Trump and the Trumps' young son, Barron, at Trump Tower. Shortly after the election, a CNN Money report indicated that protecting Trump's family in New York cost US$1m ($1.4m) a day. If they instead joined him at the White House, of course, that cost would essentially be eliminated.

Combined, these costs could make Trump's presidency awfully expensive, particularly in light of that proposed budget.

Bruce Bartlett, former government aide, tweeted: Trump is on track to spend US$1 billion ($1.4b) in 4 years housing his wife in NYC and vacationing in Mar-a-Lago virtually every week.

But that's only if those estimates are correct.

We can start with the Trump Tower number. The million-dollars-a-day figure was sourced to three city officials, reflecting the city's costs.

In February, the city of New York detailed precisely how much it had been spending to provide additional security at Trump's home. Between the election and the inauguration, when Trump was living there as president-elect, the city spent about US$308,000 ($439,300) a day. Once Trump moved to Washington, the city expects that the cost will be up to US$145,000 ($206,800) a day when Trump isn't visiting. (He hasn't since being inaugurated.) That's sharply lower than US$1m ($1.4m) a day.

It's also only the city's costs. There are additional costs at the federal level, like Secret Service protection. In 2008, the former head of that agency estimated that protecting a candidate costs about US$38,000 ($54,200) a day. Presumably protecting a spouse and young child would cost less. There were also reports about the Secret Service and the military seeking to rent space in Trump Tower to aid in supporting the president. It's not clear whether that's happened or how much space has been rented. (The Secret Service denied that it was planning to rent space.)

CNN estimated that one of the floors of space reportedly under consideration could cost US$1.5m ($2.1m) a year - or about US$4,100 ($5,850) a day. If those numbers are all correct, and if the military rents that floor, the total for protecting Trump's family in New York is a bit under $200,000 a day, including New York City's costs.

Then there are those Mar-a-Lago trips.

WATCH: Why President Trump spends so much time at his Mar-a-Lago resort

Politico's US$3m-plus ($4.3m) estimate was based on an October 2016 Government Accountability Office report on a trip President Barack Obama took in 2013. That trip, which included a stop in Palm Beach, Florida, cost US$3.6m ($5.1m), US$3.2m ($4.6m) of which was the cost of aircraft.

Air Force One costs US$206,337 ($294,300) an hour to operate, and the D.C. to Palm Beach flight takes about two hours. That's US$824,000 ($1.1m) right there, round-trip. So where did the other US$2.8m ($4m) come in?

In part, it's the cost of support aircraft. That 2013 trip included five other planes and four helicopters as part of Obama's overall team, serving defense and short-distance transport roles. (The president goes to and from Andrews Air Force Base by helicopter, for example.) But that trip also included an unrelated trip to Illinois, meaning a much more complicated ballet of movement than Trump's Mar-a-Lago trips would require.

Secret Service staffing on the 2013 trip ran about US$180,000 ($256,700), according to the GAO. Most of the cost was eaten up by those support aircraft. The 89th Airlift Wing ran up a tab of US$1.3m ($1.9m), including the costs of operating Air Force One. Additional aircraft were used to "provide global passenger airlift, logistics, and aerial support and communications to the President," which they would presumably also do for Trump's trips down to Florida. But again, that trip included a flight to and from Chicago, which is slightly closer than Palm Beach from Washington.

If we assume, just for the sake of an estimate, that the full cost of the 2013 trip can be allocated by hour of overall flight time - since the trips themselves were about the same length, one weekend, and since air support costs ate up most of the bill - we get an estimate of about US$514,000 ($733,100) an hour. (US$3.6m ($5.1m) divided by 3 1/2 hours to and from Chicago and four hours to and from Palm Beach).

A five-hour trip to Palm Beach, then, would be about US$2m ($2.9m) - US$514,000 ($733,100) times four hours. This is a very loose estimate, mind you, but it seems more fair than US$3.6m ($5.1m).

These figures put Trump's costs in a slightly different light. Sure, two trips to Mar-a-Lago still eats up the same amount as that year of funding for the Interagency Council on Homelessness, but at a slightly disproportionate level.

If Melania and Barron never move to Washington and if Trump continues to head to Mar-a-Lago for four out of every nine weekends, our estimates put the total cost at something like US$526m ($750m) over the course of Trump's presidency. Melania Trump is apparently planning to join her husband in Washington at the end of the school year, though, and Trump calls Mar-a-Lago the "winter White House," implying that he won't be there in the summer. In which case the overall spending plummets further.

To only, say, US$130m ($185m) or so. Only enough to fund the homelessness agency until 10-year-old Barron Trump is 42.