IMO.....you may want to really consider the W1000X from Buydig for $389 shipped using the coupon MayFlowers10.
I've been using the A900X and the W1000X the past week and both of them are very good value for the money. However, what is not to like with the 1000 model......wood cups, dual entry wiring with better copper than the 900, nicer wood plug. The 1000X sounds more refined too and has a larger soundstage. These phones are truly on par with at least the old and highly praised Denon 5K. (I have D5K too).
IMO, right now, I don't think there is a better closed can for the money. It is truly outstanding.
Another route to be considered is the Denon AH-D600 from Amazon Warehouse deals. There are some "very good" pairs for $222 shipped today. Returns are about as painless as it comes so 30 days of risk free tryout is nice. I just bought a pair of these because I was always curious of them.
They are highly polarizing phones. I've heard D7K users saying hey are on par with those and others saying they are worse than the beats. With all of the Faux-diophiles polluting Headfi, it's hard to say, I'm guessing they are nowhere near as bad as they are being portrayed.
I'd really be leaning toward the 1000X.....they are just phenomenal with good amplification, best bang for buck currently IMO.