Buy a $40,000 10 year old amp for $4,000 or new amp for same money?

Hi. There are bargains to be had on really high-end components that are more than a few years old. DACs change too much and we need the newer technology. How about amps and pre-amps? I know it can depend on the specific amp but in general is a 10 year old amp that was $40,000 in 2009 and now sell for $4,000 a better value than a new amp that sells for $4,000 in 2019?  How much has amplification evolved in the past decade or so? (I posted a similar questions about speakers in that forum). Thanks for all the input and wisdom.