DuckTales

 was the one thing Brad could tell Rachel that he actually treasured. It was a television show that guided his career, at least to some degree.

An animated television show from his youth, it centered on the adventures of a family of anthropomorphic ducks, led by a patriarch named Scrooge McDuck. He was so wealthy that he put all his coin into a large structure called a Money Bin and then swam around in it, leaving all the poor ducks to swim in water instead.

Brad remembered this show with such fondness that he dreamed of using his earned wealth to build a Money Bin in real life. The fact that his skeptical architect was induced to start to work on a Money Bin when given enough money proved to Brad that his real desire in life was to have enough money that he could effectively own people — or at least persuade them to do ridiculous things like build a fictional structure from a cartoon series.

Behind the scenes
This is a meta reference to the fact that the actor who portrays Brad, Danny Pudi, is a regular on the 2017 version of Duck Tales.