Sennheiser HD280 Pro, I think they are a good bang for your buck.
Sound is 100% subjective and my experience with the Sennheiser HD280 pro is not good at all when it comes to mixing and critical studio listening, or enjoying music with. They are not very linear but they are closed back and have very high external noise cancellation which makes them great when recording vocals to avoid sound bleed. For me they are perfect for that.
To me more expensive studio headphones like the open AKG K601, K701 or Sennheiser HD600 are a night and day difference better compared to the HD280. Once I experienced that big difference I can never go back.
A nice pair of studio headphones can last 10+ years when careful so I think it's worth spending that extra 100-200 to get excellent sound every day if sound is important. The money difference do correlate to sound quality, and over a few years that extra money is well spent IMO. I'd recommend everyone to take their favorite albums or recordings into a headphone store and do extensive comparisons with the lower and higher budget popular studio headphone brand models to hear the difference.