Affordable vs. ultra expensive speakers - what's the difference?

The only way to answer this question is to listen to both in the same room in a blind test! If told what you’re listening to is the $50K speaker, the placebo effect kicks in - your mind not your ears tells you these have to sound better with zero evidence.

Everyone on this site loves to intellectualize the sound with fancy adjectives that fall short in conveying what you hear. Its like watching a youtube video on your computer of a speaker demo- what’s the point you’re listening thru computer speakers.

Forget all specs and listen. If after listening, you like the $3K speakers better- so be it! Its the sound you like. Enjoy!

I don't know the differences, but in your travels, ask to demo a pair of Magnepan speakers.  You might forget about the $$ and listen to the MUSIC and buy them.

As I understand it, they have several price points you can check out.

Cheers!

To more closely answer the original query...and let's assume that they measure closely. Differences in cost can include:

* cost of raw materials
* cost of labor in the country they were assembled
* level of design sophistication (flat vs curved exterior, internal bracing, x-over design, etc)
* numbers built (economies of scale)
* other models built using some of the same parts (economies of scale)
* company reputation

I'm sure I'd missed some variables, but as most others have pointed out, what do your ears like? If they measure, or sound the same to you, then it becomes a matter of aesthetics, company trust, or emotional attachment. For instance, a new 911 Carrera will outperform and cost less than half of what a 1981 924 Carrera GTS does, but I'd rather have the latter. Go figure...

Hello OP, how are you?  I have heard the Monitor Audio’s.  I own the Hailey 2.2’s,

along with Audionet electronics and Mola Mola Tambaqui DAC, They are simply stunning in every way.  I never dreamed of owning such expensive equipment.  But you know what? It is worth it to me.  I hear it.  Loud or soft, all types of music.  All the fancy words…resolution without fatigue.  Immersing…

There is so much good stuff at all price points.  Amazing hobby / lifestyle.  Pay for what your ears think it is worth to you.  Everything matters.  Source, preamp, amp, speakers and yes, cables.  
 

You can hear the difference.  or maybe you can’t.  That defines the value.

I invite anyone to hear mine.