I checked out an audiobook of Mr. Gaiman reading the novel and what do I hear?  A light, joking conversation about expensive food in museums and attempting to use Tintoretto and Van Gogh paintings to buy them instead of money.  Before that, the author references the big museums such as the Louvre.  As he mentions these places, Gaiman observed that taking in-depth tours of these places will leave you aching and “the great art treasures of the world blur into each other after a while”. (1)  As someone who binges on museums, I found that Gaiman wrote the truth.

1. Neil Gaiman, Neverwhere Audiobook (HarperCollins Publishers) 2007.

Update 8-12-2015:  I realized how much of a mess I left this post with the additional edits I added.  I’ll clean it up by writing in this section that after I published this post, I later added a citation, a link, rewrote some sentences, and removed an old link.