I really like the B400 a lot, a little warm neutral which is still within my taste, but im plagued by QC issues
That aside, more expensive does not equal to better sounding headphones. The law of diminishing returns hits harder the more expensive you go. I paid 50 sgd for the tinaudio T2 which is quite neutral for a dual dynamic driver, and maybe get 70% of the performance of the B400, but buying a $1000 iem/headphone doesnt mean you get 5 times the performance of the B400. Just like how the B400 is not 4 times the performance of the T2.
I am a practical person, can you consistently hear the difference between mp3 320kbps, aac 256kbps and FLAC? i can only tell maybe 60% of the time, and thats when i purposely sit down to do critical listening, otherwise i might as well not care for the differences on a day to day basis. You can test your hearing here:
http://abx.digitalfeed.net
Sure, i can hear the difference in timbre, quality, decay etc in the $1000 iem and $200 B400, but the difference is too small for me to justify the price jump. Everyone has their own limits, so take your time to sit down and quietly compare.