Probably because those estimates were made 10 years ago lol
Not so.
There was time, appx 30 years ago, when you couldn't give a surplus Japanese rifle away, except with a relatively small bunch of knowledgeable collectors.
Just like the Italian Carcano, they had received a lot of bad press from the mainstream media (propaganda) to downplay the worthiness of the enemy's battle rifles. Those who knew better knew that drive for what it was.
However, the stigma stuck in some minds to present day thinking.
Both the Arisaka and Carcano were proven to be very capable and strong. The Arisaka, actually surviving strength tests, done by accredited individuals and governments, over K98s, Springfield 03s, and others.
Over the past ten years, Arisaka rifles with and without crests have, like most surplus rifles, been steadily increasing in value.
Like most surplus rifles, matching numbers, rare manufacturers, rare dates, and of rare conditions or accessories, types such as sniper or carbines, will dictate value.
The excellent condition specimens will easily fetch more than a pristine Lee Enfield, and easily hold prices with similar condition Mausers.
Many folks are still stuck in the old magazine ads in firearms magazines from the 60s to 90s. Most of those firearms, at very low prices for the time, were serviceable at best, some were Very Good. Most were Good Only.
The excellent grade rifles were still in storage or had been sold off at premium prices in the twenty years following WWII, Korea.
Today, wannabee collectors strive to get the best of the mid grade rifles.
The premium grade rifles always brought premium prices, other than for a few very short years.