I agree with nkkuma1, you did the right thing to save money, but yes, the Denon sound is addictive.
I own and love both the D7000 and the D2000. These Denons happen to fit my head and ears better than any others I've tried.
Is the D7000 worth two or three times as much? Probably not, but the difference is quite audible -- tighter, deeper bass, slightly more open soundstage. I use the D2000 for everyday work and listening, and the D7000 for my best recordings and demanding studio work (I can hear the lowest frequencies clearly, and they don't leak). For mastering, I always listen also with my AKG K702, for comparison and reference.
The audio law of diminishing returns still applies, though. So, like Beluga caviar, Super Bowl tickets, or the keys to a Porsche, only you can decide if the cost is really worth it to you. Still, with the D2000, you're enjoying the headphone equivalent of Ossetra caviar.
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