In times of inflation, art appreciates. When cash (or bonds, or equities) lose value, people spend. They buy art, precious metals, property, stamps, and alcohol.
Art is more interesting from a copyright perspective, and also a literary point of view. Thrillers have been written about high value rare coins, high value rare stamps, lost and stolen masterpieces: Charade, The Saint in Palm Springs, The Rembrandt Affair, The Monuments Men, The Last Vermeer etc.
One of the most interesting commentaries on the international art market comes from Art Law: Introduction, authored by Pierre Valentin of Constantine Cannon LLP.
Quoting a small portion:
"Owing to changes in taste, high-end and, to a lesser extent, mid-market 20th-century and contemporary art and collectibles are doing well. Old masters and older furniture are not doing as well, unless they are exceptional examples."
And, on prices for exceptional works:
"...some commentators predict that within just a few years, an [iconic example of] artwork will sell for over US$1 billion. There is a relatively small pool of international billionaires and museums competing to acquire trophy pieces. Exceptional prices have been achieved at auction when only two such collectors or museums bid against one another."
Astonishingly, works of art costing $500,000 or less are considered "lower end".
If and when one buys a physical piece of art, one owns the canvas (or wood, or paper) and the paint (or whatever medium is applied to the surface), but one does not necessarily own the intellectual property. One cannot create prints or derivative works... except in the circumstance that the creator assigned the IP by written contract.
That principle also applies when one does not own an original copyrighted work at all, as is the case with Andy Warhol and his copying of a photograph of Prince. An Appeals court has ruled that it is not transformative, and not fair use to take someone else's portrait and merely change the color of the subject's skin.
It would seem that the Warhol Estate's contention that giving a person a purple face transforms them from awkward to "iconic" is ... not convincing.
All the best,