I agree. Your gonna have to spend some money to assemble a high quality stereo. You got a rough number. One of the better stereo I have heard isYou're going to have to spend something. But the simple fact is you can get excellent sound inexpensively or you can get it expensively. Its up to you. Sometimes the really expensive stuff really does sound better. It all comes down to the intention of the designer. But if the designer is in it for the money then like any other field of endeavor its likely to be mediocre.
But many designers intend to do the best they can. Some are better at than others so we hear differences. Funny thing though the one that's better at it might not be charging as much because that isn't their intention.
I've listed examples on this thread and have plenty more. I've had time to think about it since I was first asked this question well over 30 years ago. Even then it was really obvious that price had nothing to do with it. Back then cassettes were still around and Pioneer made a few machines that used Dolby S noise reduction. If you gave them a microphone feed from a set of really good mics they could sound amazing. Sony made a Walkman recorder that could do that too. I used a Walkman for an on-location that was done in a museum since they wouldn't allow AC cords to be used. The recording came off great.
Once you understand how important the designer's intention is in the product, its really obvious that price isn't what's important.
Amps $4500
Pre $2500
Speaker $12,000
Subs $4000
Cables $3500
Source and DAC $12,000
Room and power $10,000
Processing $6,700
I know a investment as such done thoughtfully and or with DIY can create a stereo that plays Exceptionally well. Very high end.