"Audiophiles are Snobs" Youtube features an idiot! He states, with no equivocation, that $5,000 and $10,000 speakers sound equally good and a $500 and $5,000 integrated amp sound equally good. He is either deaf or a liar or both!
By now I hope everyone fully understands that OP got me confused with another youtuber (John Darko). He is the one that produced the video with that clickbait title, I did NOT.
As to the rest, price has no impact on whether something "sounds good" or not. As the risk of stating the obvious, I can make a speaker out of gold and charge a million dollars for it. It doesn't mean it will sound better. So the example of $5000 speaker vs $10,000 is without meaning in audio. Products in that price range start to get into luxury range and are often priced to what the market will accept, not what it costs to produce, etc.
A speaker will sound better than another if in controlled testing it shows that advantage, i.e. when you don't know the brand, make, history, looks, etc. Just the sound. Failing that, we can use measurements to rule out broken designs and praise the well engineered ones based on latest science of sound reproduction in rooms.
As a general statement though, a speaker that goes lower and plays louder will be more expensive. So all else being equal, a $10,000 will be better than a $5,000 speaker in this regard. This is why I own a pair of speakers that cost $23,000. It plays extremely low and dynamic in addition to being excellent in other respects.
The example of amps is also dead wrong. An amplifier can sound horrible if it runs out of power. Or have audible hiss that is annoying. Sadly you can get a $5,000 amp that is very low power and hence clips. And or have audible artifacts. Or it can be superb with all the power you need. The only way you know is again, using controlled listening tests or measurements. Random opinion by Joe poster online or youtuber may not apply I am afraid.