[Neijii]

I'm not sure if this is like desktop computers vs laptops, where in desktops you'll get more of a computer for the money. Does the same apply for on ear headphones vs IEMs?
 
I love my IEM, I spent about 150 them. Was wondering if a $150 full size would have better quality?

 

[kuriousmax]

I think full sized headphones typically produce higher quality sound.  But such a general statement will always have exceptions.  I've used IEMs for years but recently bought some full sized headphones and they are definitely more detailed.
 
Both types have strengths and weaknesses and they were designed for different purposes, much like laptops and desktops.

 

[DrKrFfXx]

I have a pair of Shure SE215 IEM and a pair of Sennheiser HD449, full size, they costed me about the same, and I couldn't rate any of those higher than the other in sound quality. Both lacks in some areas, both shine in some others at their price point,
 
Aside from that particular example, I'm on the same boat as Kurious, usually full size headphones have more raw material to work with, more air, more space and thus, it produces a higher detailed sound at lower price points.

 

[Sound Quest]

Unless you're planning on buying something like these

- http://www.whathifi.com/review/akg-k3003i
 
Then you're probably better with full sized headphones.

 

[Tsujigiri]

In general, a full sized open headphone will sound better than anything else for the price. There are of course exceptions. Also, full sized headphones tend to last longer than IEM's. IEM's can't be beat for portability and noise isolation, though.