It all depends on where you shop.
I could use wires for my PS3 with the PC too if I wanted to play it on a big TV. For my PS3 for example, we have an optical cable, HDMI cable, and ethernet cord specifically for it. They would work on my PC too and all I have to do is bring it out and place it almost exactly where I place the PS3. Even though my video card isn't HDMI out, it's still HDCP so all I'd need is a DVI-HDMI adapter for a couple of bucks and that takes care of the sound and video. For my keyboard and mouse, all I'd need are some usb extension cables and they would also work nicely for playing and charging my PS3 controllers.
DVI to HDMI $3.20 - Don't know if this would be one I need, but it illustrates the price.
15ft USB extension $1.73 - Great not only for extending the reach of the mouse, but also for PS3 (or 360) controllers)
15ft PS/2 extension $1.62 - If you're like me and use an old keyboard and don't have a PS/2 to USB adapter, this should work.
