Well, they just introduced some new equipment.
$5000 for the monitor and $999 for the stand, or if you have your own stand the Vesa adapter is a mere $200.
The New Big box can support up to 8 of those monitors, can I sign you up?
$1K for the optional stand is indeed asinine, but then again my desk already has movable monitor arms, so I don't use stands, anyways, nor do many others, and inexpensive ones are plentiful.
However, you are leaving out the highly unusual specs that make the $5K "Pro Display XDR" worth $5K, for those producing HDR video:
You have to compare this to other "reference monitors", which are also in a different league.
Besides, it isn't like you can't just run into Fry's and get the best 4K 32" monitor on sale that day. All these parts have commodity options these days.
Want to expound a little on the value you get at those prices then show us how to build a similar equipped PC for one tenth the cost.