A new Senate report pegs the cost of the last three government shutdowns, from the bizarre 2013 Republican shutdown demanding the end of "Obamacare" to the two 2018-2019 Trump-led shutdowns over whether or not he would be granted taxpayer funds to build his Great Wall of Racism, at about $4 billion dollars. That's $4 billion dollars from American taxpayers that was effectively lit on fire by Republican hostage-takers, in addition to the closure of government offices, national parks, and other non-"essential" facilities.
The vast majority of the bill, $3.7 billion, represents back pay to furloughed federal workers. Those workers aren't paid, during shutdowns, often resulting in enormous consequences (missed rent or mortgage payments); when Congress eventually returns with its tail tucked between its legs to solve the self-imposed crisis, they typically restore that back pay in an effort to keep federal workers from quitting en masse. Other costs might include the cleaning and repairing temporarily abandoned public spaces; in an effort to soften public anger at Trump's longest shutdown, the administration attempted to keep some parks open even without staff to monitor them, with predictable effects. The Senate report does not include the costs to all government agencies—such as the Department of Defense.
What did the American public gain, in exchange for that $4 billion? Nothing. Not a thing. Closed parks, closed government offices, delays in critical paperwork, licenses and so forth, with a fat bill attached. It was done for no reason other than self-promotion by sets of posturing Republican cranks; none of the three recent shutdowns came with a Republican plan for how "shuttered government offices" would result in "Obamacare goes away" or "Trump gets funding for a boondoggle project so absurd that even unified Republican House and Senate rule had refused to pay for it."
There you go, then. A trillion dollars in tax cuts to the wealthy, a few billion here and there for Ted Cruz or the Idiot in Chief to use as fodder for fundraising letters, and a party-wide commitment to pumping both private and government cash into Donald Trump's pockets via his own still-held for-profit businesses.
To be sure, some American taxpayers will find all of this worth it. They are extremely devoted to Republican Party racism and conspiracy-mongering, and are willing to piss away quite a bit of their own paychecks in order to prop those things up. Those costs are getting steep, though. One wonders how many in the Republican base are fully aware of that.