Many luxury watches increase in value over time. It happens because production of a specific line stops, making the watch rarer and more valuable. That increase in value is however nothing compared to the increase you see when a vintage watch was owned and worn by an a-list celebrity.
Just how valuable a watch like this can be was demonstrated in 2012 when a watch owned by Eric Clapton was sold for £2.14 million to an Asian businessman. The wristwatch was a Swiss made Patek Philippe from 1987. It features a perpetual calendar with moon phases, it also has windows showing the day and month. Very few of these platinum plated watches were ever made.