Lady Gaga
Lady Gaga dropped $50,000 on a "ghost detector" device after becoming concerned that her house was haunted. Jokes on her though, because the scariest thing about this whole ordeal was the price tag.
Michael Jackson
In 1985, Michael Jackson purchased the rights to the Beatles discography for $47.5 million, which caused quite a stir at the time. He was close friends with McCartnery prior to this... guess buying your friends music out from under him isn't a great look.