You can probably ask around for white box versus purple box M50.
Both of my pairs are white box (one regular coiled version and one straight cord limited edition), though.
At the end of the day, the M50 is not the absolute best value at under $200 in my opinions. There are many headphones I can think of that match it, and some more that beat it depending on many factors (listening preference, source quality, amp, etc...). As such, I don't think a lot of people own 2 M50's deliberately. The only reason why I have 2 now is because my dad didn't want his pair anymore. He moved up to speakers.