I feel that dacs hit the wall of diminishing returns the fastest. It's practically a zero cost for most people as the built-in whatevers of their devices for the most part are "good enough".
C'mon man, minidisc or bust
Slightly more OT than we already are: Was one of those 25 closed portables by chance the Shure SRH1540? If so, what were your thoughts on that one?
Even the "upgrading from Beats" crowd you see on Reddit is hilarious...The amount of V6/7506 I see despite legitimately sounding like holding tin cans with string up to your ears and with some asshole bashing them with a tuning fork every time a cymbal or snare plays.
I like to think in terms of TOTAL SYSTEM. Plan a budget for an entire system.<$1000...<$5000...<$15,000
Apart from the Stax, KGSSHV and Yggy total system configuration that I have, every other configuration has Yggy as the most expensive individual item (or roughly equal to the amp in case of the ZDS) in the chain.