Sorry for all the potty humor around here lately, and, well, you've probably already heard this, but JD Salinger's toilet is for sale on eBay, advertised as "used" and "not cleaned". You only have eight days left to bid on this item, which has a "buy now" price of one million pounds.
With a price like that, the seller outta consider offering it as buy to let (groan).
To put this in perspective, back in 1999, a signed copy of Duchamp's "Fountain" sold for 1.7 million dollars.
Still unsold, to the best of my knowledge, is a toilet that Hemingway "rescued" from, if memory serves me, the demolition of one of his favorite Key West Bars, and set up as a fountain or birdbath in the courtyard of his Key West home.
Curiously, there's a webpage about the world's most expensive toilets, which includes something in outerspace, but which lists none of these three artist-related commodes.
One last piece of toilet trivia to ponder the next time you're perched upon the throne: Leave it the US to build two-story outhouses.