If you take a brand new $1,000 Yamaha, Onkyo, Denon, HK, Pioneer, Marantz and compare them to a brand new $4,000 Arcam, NAD, etc., they will sound very similar when you BYPASS all Tones, EQs, & DSPs.
Just look at the actual MEASURED Specs - SNR, THD, Crosstalk, Frequency Response. They all measure about the same, and they all sound about the same.
However, over TIME, parts will degrade.
Thus, I think over time - say 10 years, the $4,000 components may RETAIN the sound quality better than the less expensive units.
So just buy new components every 5 years.