It's worth the cost, given the fact that a computer holds considerably more value in terms of usability. You can't write a resume or edit videos on a Playstation, for example. (Well I'm sure you could if you were determined enough, but you get my point.) And like I said, accessories like controllers are generally more expensive on consoles, and you have to pay a monthly fee to play online. This stuff adds up quickly; you've paid less up front, yes, but in the long run you spent more on your console than you would on a PC over the course of its lifespan.

Not to mention that PCs work just as well in the living room on a giant TV. I'm typing this comment from such a setup. Keyboard in lap, mouse on either the armrest or a table directly to the right of it. It's very comfortable.

Lastly, I get the resale argument, but it takes decades for most games to gain enough collector's value to be worth my time to sell it (if it ever happens at all). More often than not, you'll get $5-10 at best if you're lucky. It's cheaper in the long run to just take advantage of Steam sales, and there's the added bonus of getting to keep your games forever.

edit: Also, mods.