I agree more than I wish to admit. And not only diminishing, but diminished. Meaning it completely stopped justifying the high price in every possible way. You can get the looks, the build quality and the performance for much less. There's no return still diminishing. You're just left without the silly name. The name is actually what has been bestowed upon Kenny Rogers after he was mistakenly accepted to Valhalla.
Anyway, these outperform the Kennerton for a small fraction of the price and this time it is not a subjective preference:
Studio and DJ Headphones Closed, Circumaural, Impedance: 63 Ohm, Sound pressure level: 106 dB, Frequency range: 10 - 20 000 Hz, Cable length: 1.2 m, 3.5 mm jack plug, Screw-mounted 6.3 mm adapter, Weight with cable: 298 g, Weight without cable: 230...
www.thomann.de
Ah yes! The old reliable sony 7506. I used to own them for a period of time, along with the MDR-CD900ST. Soundwise I don't enjoy them as I do with my current headphones but they were really neat, and that was before I started to try EQ so they might actually sound even better had I applied it. One thing I extremely love about those headphones is that they're so durable and reliable. I'm really sick and tired of the so-called apex headphones having driver issues and build quality problems (thinking of some models from hifiman, focal, audeze and more...) while my hd650 and beyer 990 are maybe 10 years old or even older and they still work splendidly.
Back to price diminishing topic. I think it's up to what standard we use to evaluate something. If we use objective standards then it's clear to see that most products are more expansive than what they should be, in comparison with other competitors of the same class.
But if - if our sole reason in this hobby is just to buy whatever we enjoy, then even if I buy a $10,000 headphones that measure like somebody practiced zig-zag lines on the chart, as long as I can enjoy that headphones to the fullest and feel like I truly like it, then the purchase is easily justified.
So it's really up to the purpose of a person. With real objective, measurement criteria we should be fair and just, or even a bit harsh. But with subjective aspects, we can't really say if something is right or wrong because we don't truly have something we can use as the norm standard, so with that I think we should be lax and respectful toward other people's experiences (sometimes, some folks here bash other people's experiences a bit more than they should).