For a small budget like that if I was you I would look at IEM type headphone like the Vmoda Vibes (www.v-moda.com) or offerings from Shure or UE. You seem to value sound quality, so if your budget grows later on you can look at the AKG 271 or even quite a bit better and more expensive, the Audio Technica W5000
After some research I'm leaning toward the IEM type . I have had a headphone amp for audio quality so maybe comfort and durability should be considered more important ?
Well comfort is very personal, you'll have to go try them out. I myself can't stand IEM phones other then the time spent in the public transit or at the gym. For my taste most full size headphones (except Grado) are fairly comfy. I sometimes listen my Audio Technica W5000 when I go to bed and I could listen to them for the whole night if sleep wasn't a human basic need!

As far as durability, I think your budget will determine durability!

If you have a really tight budget, you'll be satisfied with whatever you buy, if your budget is flexible, you might buy a $100 set right now and want to change it for a $500 pair in a few months. That's the never ending story of audio, but it's fun!