In that case, I'd save my money and buy a less expensive headphone - perhaps the HE-500 - and get a good amp to drive it (assuming you already have a good source already). It's a chain of components that makes the sound and thus determines sound quality. Headphones are the most determining in terms of sound character and quality, but they still need reasonably good amps and sources to play what and how they can.
I'm currently planning on getting the HE-400, it's efficiency, comfort, and similar sound for a cheaper price is just too good to pass IMO. I'm still considering the HE-500/HE-6, but I will most likely go for the HE-400.