Great poll! I completely agree with your premise, that there is "point of absurdity", and one of the things I'm trying to do with these online conversations, is to get some ideas of where that might be. I've already figured that $100,000 for a pair of stereo speakers is probably well past that line!
I've also been auditioning stuff, and have heard some fairly amazing things, like having the rear wall fall away and the soundstage more than double in size and reach out to envelop me... listening to 2 channel stereo only! SO much so, that I accused the sales dude of pulling a fast one, and I got up and walked over to the surround speakers, nope, they were off! THAT'S what I want. BTw- that was with an Arcam AVR 200 receiver driving Linn Ninka speakers- though there were other things about the linns I didn't like.