[ZapX629]

 
I have to have this on for hours sometimes... do you think MSR7 is just as comfortable for that kind of duration ?

It depends how they fit you. If your take the time to stretch the band a little and space out the cups, I think they're fine, but everyone is different. You can always give any headphones a trial run from Amazon and make sure they work for you.

 

[Dexter22]

If you are interested in the Senn HD598 and want to save some money then just buy the HD558 model instead, exact same driver with a bit of material added to block a bit of the highs which can be removed if wanted. I use mine stock though and perfectly happy with them, I did own HD598 too but gave them away as a gift so replaced them with HD558 to see what the dif is and it is very little. I actually prefer the black color of the HD558 over the cream of the HD598 but I see you can get HD598 in black too now.

because of his specific requirements, i think this is out of cinsideration')

 

[Griffith]

Not sure if these are the best choice for your intended usage but I think I would go with either the Sony MDR-A1 if you want an all-round good sounding headphone with nice bass, good clarity and great comfort. They are 1 cent short of your max budget whereas before they used to be considerably more expensive.
 
If you want a more neutral-sounding headphone with great clarity and just solid performance overall (though perhaps slightly worse comfort and arguably worse buid-quality and aesthetic) then I'd recommend the Fischer Audio FA-003 or Brainwavz HM5 (they are the same headphone, Brainwavz licensed the headphone design from them).
 
The Brainwavz are considerably cheaper and I don't think either will disappoint you in terms of sound quality but if you're going to be wearing/using the headphones in public I think the Sony would be a better choice because of aesthetic and design reasons (the cable and physical size of the Brainwavz being one of them).