I got the $80 Crossfade LP. I also have the M50.
The M50 is easily the better headphone. Now I know everybody has different preferences, but generally more expensive headphones = more neutral/balanced, as opposed to cheaper headphones that have too much bass and not very detailed. The Crossfade LPs are the latter, while the M50s are the former. And it's not even that the Crossfade LPs have that much more bass - maybe just a bit more. But the sound is quite muffled, and the highs and mids just don't sound right. M50, meanwhile, is very balanced and natural. I can barely stand some of my sub-$300 IEMs anymore after the having M50s. I've been using my Westone W4R and Sony EX1000, along with my M50s.
Comfort wise, the M50s have a much more cushy and flexible headband. I find the one on the LPs too tight and clamping. The M50s have big, comfortable ear cups that go around your ears. The LPs are more on-ear. They have much smaller ear cups that parts of it will be pressuring on your ears.
Obviously the design of the LPs is quite flashy. The packaging and unboxing experience is phenomenal. The M50s, on the other hand, was just simple one-step sort of unboxing - take it out of the box. But the white version looks quite good I must say. Although I love my black pair.
Soundprofessionals.com has had the M50s on sale not too long ago for $100 +shipping, if you can find the M50s for that price, I'd just go for it. Again, if you don't really know much of this stuff, you really can't read too much into people's opinions. You cannot go wrong with the M50s though - they've been here for a long time and remained very popular headphones. They are known for excellent sound quality, price-to-performance, durability, and comfort. They will always be in demand so you won't have trouble selling/trading it. What more can you ask for? BTW I am totally returning my Crossfade LPs next week.