What is, or would be, you most expensive listen?

I'm talking source material and the apparatus to play it. Mine would be Pink Floyd's Dark Side of the Moon, the original Alan Parson's mix in discrete quadrophonic.

I've seen the only source discs that have this are about $200 on Amzn. Then you need a certain player - OPPO is mentioned - just to decode it into 4 analog outs. There's other players that can do this and the investment ranges from a few hundred into the low thousands.

Then you'd need 4 amps, 4 identical speakers - not the "ambient" version of an LXmini for ordinary HT playback. This is because Alan was doing location modulation of sound, not just hall reverb on the rear channels. I suspect that slow Leslie organ sound you hear on the two channel mix is doing something much different in the discrete quad mix.

Anyway, to this day I've never heard it. It's expensive to do so. What's your most expensive listen?