This headset connects to your computer with a long cable. You can sit down or walk around your room with this headset on, but the walking space needs to be empty. This headset comes with camera that need to be mounted to the ceiling in order to track your physical movement. If that is something you aren't comfortable setting up, see the Oculus Rift below.
Estimated price: $800 per headset; comes with controllers, tracking cameras
Virtual Reality Headset