Is it worth spending $90 for headphones?

[Mississippi Steve]

I don't know anything about iPods, but I think that most of them also use a cheap op-amp for their headphone jack.

For the most part, I agree with you about Koss.

I have the Koss ESP/950 Electrostatics, and they're fantastic - and sound even better when powered by batteries in the source equipment and the supplied amp. The only drawback is the amplifier, which is built kind of cheap. But, the product is guaranteed for life. I've never needed to send the phones, or the amp, back to Koss for repair or replacement.

I have both Koss Pro4AAA and Koss VFR-Technician headsets... both are over 30 years old and are still in top condition, never a problem with either, ahd you can get replacement ear cusions for them.