Thank you. Another factor would be how pricy is the required amplification for these cans ? I guess If I spend on one of those I won't be able to spend in a pricy amp for a while.
If you are never going to buy a headphone amplifier, then I would not suggest spending $600+ on headphones.
It is okay to wait until you have saved your money, and just use them until then. But if $700 is your total budget, then you should get a $300 headphone (like the Mad Dog or HE-400) and get a DAC and an Amp for $200-$400.