It's true, my opinion is always try and get the best that one can afford, instead of compromising. A lot of people would say that certain headphones have to be matched with a certain amp with certain cable to sound good, I think that is so ridiculous. If a pair of headphones doesn't sound good with a flat reference amp, that means there's something wrong with them already, if they need a specific amp to correct that, it's like putting 2 wrongs together to get one right. To me, the LCD-2s sounds right whether they are fed directly from a Cowon audio player or from a reference class amp or the headphone out of a DAW interface, there may be a slight difference, but is it a $1500 difference? I don't think so, in fact I probably get more of a difference from wearing the headphones in a slightly different position around my head.
I think the sound quality is not the important thing for musicians, the satisfaction one gets from playing a musical instrument is a lot more than what one can get from just listening. I get far more enjoyment from playing rubbish on a cheap upright than listening to Lang Lang playing Chopin on a Steinway grand, I guess that's probably what your brother thought.
'Tears in Heaven' is a great song, it moved me the first time I heard it on the radio (a cheap portable cassette radio combo), I've heard it on much better sound systems since, but did it move me more than the first time I head it? The answer is no. To me, a great piece of composition would sound great even if it's played with equipment of lesser quality, but if the music in itself is not of high quality, no enhancement in sound quality could improve it much. I'd rather listen to old recordings of Nat 'King' Cole singing than Justin Bieber in 24bit/96Hz.
I think hearing his perspective did bring me a little back to earth WRT my obsession with fringe tweaks (battery power, cables, and jitter etc). But the LCD2s alone really showed me how ineffective it was to spend so much on the HD650 on fringe tweaks...when a single upgrade to the LCD2 was the only genuinely effective upgrade worthy of the price I spent on it, along with a nice amplifier and dac for it (I've totalled probably 4.5K worth in fringe tweaking). I believe that is how he thinks, you could spend the money on a real guitar, that sounds like...a real guitar, as opposed to trying to recreate a real guitar.
I did briefly play Eric Claptons "Tears in Heaven" for my brother with the LCD2s for which he was quite stunned and remarked that he never heard this song properly before, there was so much in that track he never knew existed. (That's a real song of how deeply emotional man really is...this song was about his son that was killed in a car crash as a young boy...not today's whining boys stupidly depressing "music" about things like being rejected by girls and the meaning of life...etc...or girls happily boasting about how nasty and dirty they are or were. )