Others' Island (spoilers all books incl RWC)

[Farseer]

When people seek the prophecies or sooth-saying of an Other from the Island, they place two gold coins on its tongue. While I think we have firmly determined that they get most, if not all, of their 'far-seeing' ability from the waters taken from around She Who Remembers, WHY do they ask for a coin payment? Of what use is gold to an Other?

I thought of this previous post while re-reading the part in AA where the Red Ship Raiders demanded gold to be paid in exchange for Forged hostages to be killed. There may or may not be a connection, given we know, post-TM, that it was the Pale Woman who was pulling all of the strings at the time, but the "gold" jumped out at me.

EDIT: Sorry, the passage re gold as payment for Forged hostages comes from Chapter Nine in AA, 'Fat Suffices'.