People that really enjoy well reproduced music do not generally hear a law of diminishing returns. They hear and are rewarded with a much more emotionally involving experience. The closer and more involving is worth the increasing cost to get there. Last year with a some reservations purchased a $22K streamer, replacing my $4K streamer. Within a few minutes the price went from ridiculously high to a bargain as the performance increase was so profound and exceeded my expectation.
I have heard VAC equipment periodically throughout the decades I have pursued high end audio. Whenever I have it was always priced appropriately for its amazing level of performance. Also, yes, you cannot play a marketing trick on high end audiophiles and stay in business for a few years let alone decades.
Those of us who have pursued this for most of our adult lives are pretty familiar with this phenomenon. It is what keeps us enthusiastic about the pursuit and enjoying the music. The performance of Etta James in Canada from 1975 that is currently playing is truly amazing and with a realism I never imagined I would experience… and from Qobuz, the streaming service. Amazing.