I agree, not just about speakers, but about audio equipment in general, keeping in mind that the knowledgeable audiophile quickly learns what is worth spending money on and what isn’t. By the same token, with experience one generally has a pretty good idea about the point of diminishing returns. Spending a lot of money on speakers? Shop carefully, audition them in audio stores, and go nuts to the extent you can afford and justify, because they’re really important and the quality differences are vast. Amp? Make sure it has adequate distortion-free power across a wide frequency spectrum and all the functionality you need, and that’s about it. I wouldn’t go overboard; for a typical system, not a concert hall, I’d probably draw the line of diminishing returns for a decent amp at under $1000 or less.
The whole business of turntables and vinyl is an interesting discussion in its own right. I wouldn’t claim that it’s necessarily “better” than digital, specifically CDs, but it’s different, and often equalized differently. That, and various other aesthetic and nostalgia factors make a turntable an interesting accessory in a sound system. But spending $12,000 on one is just ridiculous.
I appreciate great sound as much as anyone, but overpriced cables have to be among the stupidest things that people waste money on. $50,000 for speaker cables? I use lamp cord from the local hardware store and I challenge anyone to tell the difference. The important thing is to use wire of sufficient gauge for the power being delivered, and to have the speakers wired in phase.
Quality matters to a limited extent for high-performance digital signals like HDMI, but even there cables delivering perfectly adequate quality can be had for very reasonable prices. As long as it’s rated for the speed/resolution being used and doesn’t generate errors, and the connectors are sturdy and reliable, it will deliver exactly the same video and audio quality as a cable costing ten times or a thousand times as much.
The funniest ripoff has to be that $17K power cable. I wonder if anyone buying such a thing has given any thought to the fact that it plugs into a wall socket, behind which is whatever cheap crap the building contractor decided to use running for hundreds of feet, then connecting to a vast mess of a utility grid for perhaps a thousand miles or so. The only power-related thing that may sometimes make sense for high-end equipment is a power conditioner or a good quality commercial UPS.