Trump’s travel expenses have been the subject of an enormous amount of scrutiny. Some of that attention is merely partisan ire, just as much of the attention paid to Obama’s (and Bush’s, and Clinton’s) was partisan ire. Still, as is so often the case with Trump, the old conversation about presidential propriety takes on new meaning, in large part due to his decision to spend so much of his time at his own properties, effectively turning the government money he’s spent traveling to Mar-a-Lago and elsewhere into revenue for his businesses.

Questions about just how much Trump’s visits to his Florida estate were costing taxpayers were recently partially answered thanks to a Freedom of Information Act request by the conservative legal advocacy group Judicial Watch. According to documents regarding the first weekends of February and March, both of which the president spent at his resort in Palm Beach, the flights to and from Florida alone cost taxpayers almost $1.3 million. Judicial Watch’s figure doesn’t fully answer the question of just how much Trump’s travel costs taxpayers, as the documents don’t detail the costs of securing the premises for the entire weekend. Some have taken to estimating the sum based on reports on the Obama administration’s expenses from the Government Accountability Office; the most widely cited figure is in the vicinity of $3 million per trip, leading some to posit that Trump spent more on travel in his first 100 days than Obama did during any single year of his presidency, and is on pace to spend more in his first year in office than in Obama did in his eight.

An additional window into Trump’s travel expenses comes from the recently-passed federal budget, which has allocates more than $120 million to account for the Trump family’s protection this year; roughly half of that sum goes to New York City and Palm Beach for “extraordinary law enforcement personnel costs,” the former for around-the-clock security at Trump Tower in Manhattan and the latter for Trump’s frequent visits to Mar-a-Lago. The New York Times enumerated some of the types of costs that money could cover, such as the $300,000 per day it cost to protect Trump Tower between the election and Trump’s inauguration and the $60,000 the Palm Beach County Sheriff’s Office spends on overtime each day Trump is in Florida.

Underlying the questions about Trump’s travel expenses is his decision to spend so much of his time at his own properties, which means that at least some of that money likely goes to the Trump Organization and, by extension, Trump. By spending so much time at his resort in Palm Beach, Trump is, whether he intends to or not, effectively driving up its value because of the power and prominence of his office. On top of the enormous amount of free publicity his weekend trips provide—each visit guarantees that the property’s name will show up in headlines around the world—his presence creates incentives for both well-wishers and anybody seeking to influence the president to pay up for a membership in the hopes of catching a glimpse of the commander-in-chief. The same goes for the golf course in Bedminster, whose members pay the Trump Organization between $75,000 and $100,000 in initiation fees and $22,100 in membership dues each year—a sum that has suddenly gone from a steep price tag to play golf to an investment in the possibility of meeting the president.