‘Obsession’ is the word. We’re easily persuaded to buy things when they throw in a cheap freebie, especially if that cheap freebie is perceived to be limited in number (a limited edition of 100,000!) or if it’s something of a lottery if you receive one. Some people obsess about the pieces of paper that come with steel books.
My True Lies 4k came today. I’m about to watch it. I have a 1080p download of the movie, I’m not going to BUY a bootleg!