Headphone Quality for Sound Card to Matter

Well I was just wondering how good your headphones have to be to make a soundcard worth it?

 

It seems only logical that if I have a $20 mic/headset and lets say a xonar phoebus it wouldn't do anything and that if I have a shit soundcard and $400 tritions nothing would happen.  I want to strike a balance and I've come up with a couple "solutions" that apeal to me.

1. Get the RoG R4F that has "onboard" sound and a RoG Vulcan Pro.

2. Get the RoG R4F, RoG Vulcan Pro, and a Xonar Phoebus. (Just not use the "onboard" audio)

3 Get  the RoG R4E, RoG Vulcan Pro, and a Xonar Phoebus. 

I realize that these components are very specific but they're what I want and in the rough price range.

They increase in price as they go down.  Would there be a large difference in quality between 1 and 2 or 2 and 3?  Would the Vulcan's even see an increase with the Phoebus?

 

Thank you to all who respond in advance,

~Emo

i do find that the forum glitches sometimes so it may be that, dont jump straight to thinking that they are reposting