I've played it. It was at Jillian's in Boston in the mid 90s. Cost $5 a play, IIRC. You would put the headset on and play a very Dire Straits looking FPS in a world full of random polygonal objects. You would compete for the most kills against however many other players were in there at the time. I think it was like 5 minutes or so and it was timed without any other real objective. I only played it once or twice and by the time I figured out the controls it was over. I wouldn't be surprised if it DID cost $120k back then... it was pretty immersive, even if the software kind of stunk, and was really big.
That would be sort of cool to have in your gameroom if you could get it for the cost of a pinball machine or less. I think you'd have to have two of them, though, at least or you'd just be walking around looking at cones and spheres.