One more time. Lets say, he TAKES HIS SALARY. His private money. Does not put it back into government. HIS MONEY FOR HIS PRIVATE USE. Then, another 800 K is used by government to fund these programs.
800 K. HIS SALARY EXPENSE.
800 K GOVERNMENT FUNDING EXPENSE FOR Programs.
TWO EXPENSES.
Since the concepts aren't sinking in, let's try a real-world example where only the numbers are changed.
My company pays me a salary. For the purposes of illustration, let's say they pay me $800K. I choose to tithe to my church. For the purposes of illustration, let's say I tithe at 100% and give my church $800K. Just because I give $800K to my church does not, in fact, mean that my company does not pay my salary of $800K. My company has had a net savings of $0.
Spoiler alert - in the above example, my company would equate to the American taxpayers, I would play the part of Trump, and my church is the stand-in for the VA/Parks Services/anywhere else that Trump donates his salary.
You are getting confused with real savings versus opportunity costs. I will agree that the VA, Parks Department, or whoever else that Trump donates his salary to can then use that money to pay for things they might not otherwise have been able to. Just like my church can use the money I tithe to them to buy additional Christmas baskets and send missionaries to Nepal. But once more for posterity, the net savings to my company is $0. They still have an expenditure on their balance sheet for my salary, just like the taxpayers still have an expenditure for Trump's salary.
You also appear to be assuming that if Trump doesn't donate his salary and keeps it for his own personal use instead, then the government would for some reason provide an equal amount of money to those departments. And that is patently untrue. In our earlier example, if I choose not to tithe my salary and keep it in my own pocket instead, my company does not provide an amount equal to my salary to my church so we can buy Christmas baskets and send missionaries to Nepal. That's the opportunity that is lost if I keep my full salary for myself, but my company is not part of that equation.
AND SHOUTING IN ALL-CAPS OR BOLD TYPE WILL STILL NEVER CHANGE THAT FACT.