It’s just how they tier things.
E5000 is precision and E4000 isn’t. The E4000 is considered the 12th generation of the “core” line and they say 20% lower noise than the E-480.
But it’s only for a given generation. The E600 was a “precision” model in 2013 but it has more noise than the current E4000.
Maybe a good comparison is the “GT3” moniker for the Porsche 911. It tells you that it has more performance than the plain one that isn’t a GT3, but a 911 GT3 from 2003 won’t be as nice as plain 2024 911.
So a 2024 Precision Accuphase against a 2024 core Accuphase is different than a vintage Precision Accuphase.
The E-270 didn’t do great here but is one of the highest class AB amps tested here. The official specifications of the E-270 is pretty lousy since they made a big jump in performance with the E280 and if you look at something like the E-5000, you can get really impressive measurements.
As
@dualazmak will tell you, part of the cost of Accuphase isn’t the performance — it’s the customer service. They keep inventory of spare parts for an extended period of time and pick the amplifier up from you if you need service (if you live in Japan). When there have been major natural disasters, they have offered free/subsidized repairs for Accuphase owners, digging into the “insurance” you prepaid as the original purchaser of the Accuphase.
Since they are privately held and basically have no interest in expanding/growing if it adds risk to the financial stability of the company, so they make what they make to stay profitable and charge what they need to stay profitable and keep the lights on. So far, the demand is kept up with their asking price.