I put probably $1500 into WoW from expansions and monthly subs. In college, I passed up selling my account in vanilla for $2k ... I had a local offer on the table from a friend of a friend, which would have been a safe transaction. I didn't sell, which turned out to be a good thing because I met my wife on WoW (been married 5 years next month). Totally worth it, obviously no regrets about that.
On the other hand, my Steam library sits at ~220 games from various bundles, sales, and "WOW I MUST HAVE THIS" purchases. They're all installed on a 2TB drive, but I think I've actually launched maybe 20 of them, and actually completed maybe 8-10. I think the average is less than $5 game because I only bought on sale or in bundles, but even 200 games at $4/game is $800 I could have used elsewhere.
I've also bought & sold Xbox 360's twice, before buying a 3rd one when Halo Anniversary was announced. That got played for maybe 3-4 hours. I bought a PS3 for God of War, then sold the console & game without playing it. A year and a half ago, I spent $350-375 on a CH stick/throttle/pedals for Star Citizen, but have since completely lost interest in PC games, so that's going up on Craigslist at some point. Hopefully I can get at least some back. And last summer I bought a PS4 for Bloodborne & Xbox One in anticipation of Halo 5. I put 90 or so hours into Bloodborne (platinum'd it) and maybe 5 hours into Halo 5. Neither console has been turned on for anything but media streaming in over 2 months; and we just got an AppleTV for HBO Now, so now the consoles sit unused again.