Do hi-end DACs offer true value or diminishing return...

These two hi-fedelity recordings posted on Youtube allow one to audition the state-of-the-art, highly raved R2R DACs with values ranging from $850 all the way to $6,500. Please use headphone or, play back to your stereo system if you think your system is revealing enough. The question to ask to yourself is that the true hi-end (w/ high price tag) gears offer you true values or just a diminishing-return foolproof. In my system, I do hear the differences but, to me, the differences might not be that significant to justify the luxious spending. Maybe my system is not revealing enough.  Maybe the recording quality through the on-line broadcasting degrades.  How about you? Do you hear major differences? 

Terminator Plus ($6.5k), Venus II ($3k)

Terminator $4.5k, Ares II ($850)

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