His pop-art is nothing special. (A soup can? A banana? Groundbreaking.) Warhol loved the "ready-made" asthetic espoused by Duchamp, an artist known for a piece where he simply bought a urinal and turned it on its side (It's called Fountain). THESE GUYS ARE WHY PEOPLE DESPISE MODERN ART.
On top of that, many of Warhol's pieces weren't made by Warhol. He had work-for-hire artists produce his art at The Factory. This started the awful trend towards art factories.
Let that sink in.
He made a self-portrait in a photo booth and silkscreened it blue.
It's worth $38.4 million dollars.
But the real nugget of wisdom in the story is this; The market for high-end art is small (most of us don't have a couple million to throw around), but dedicated. One of the collectors, Mr. Mugrabi, owns over 800 Warhol pieces. At a price range of millions of dollars per painting, this guy is both rich and a HUGE fan of Warhol.
There's nothing more important to your band than your super fans.
The average fan will only drive up the value of your art so far, but it's the super fans who stretch the high-end of what your work is worth. Deluxe edition of your album? They have it. Limited tour T shirt? They have it. Signed drumstick sold on ebay? They want it.
And these super fans signal to the rest of the world that yes, there is something very special about this artist/band. Remember the Fan Velocity concept I introduced?
Super fans are your disciples. Make them happy and they'll stretch the value of your work beyond anything a marketing campaign could ever do.