5.Patek Philippe Ref. 1518 in Stainless Steel – $11 Million
This watch, which is the first in an extremely rare four-piece series, was just recently sold at an auction for the staggering price of $11 million. The cases of most Patek Philippe watches are made of rose gold or yellow gold, but the one on this watch is made of stainless steel, which is one of the reasons why it is so uncommon.