Unless you are in need of super precision cut, replaceable blade saws are good enough for most of the work. But when you need that super accuracy, for where it counts, and also to save time, because you don't have to fix the cut surface too much or at all if you are skilled, these ultra high quality saws are still very useful in many scenes. Again like Yokoyama "En", Heiji's saw has this special aura.... which seem to transcend into something more than just a tool.
His saws are very expensive. But there's a good reason for the price. You won't be surprised if a plane blade would cost this much. But "genuinely hand forged" saw making involves much more effort than plane blade making, so the price is low considering that. At the moment there are only two who knows how to make genuine saw. One is Heiji and the other is Takiguchi-san from Kawagoe.
Mitsukawa-san is a young energetic saw maker who's trying to ACTUALLY EAT with the saws. That is something RE~~~~~ALLY commendable, considering the fact how difficult it is after the introduction of the rep blades. He studies the market and makes various saws of various grade (prices).
On the other hand Heiji has given up making a living with saw making. He learned to make high quality plane blades and various knives instead to support his family. He went to see Iwasaki-san (the most famous living blacksmith in Japan) after he was already a famous saw maker....
He didn't want to sell lowered quality saws (ie the unforged ones), so that wasn't in his choice. He didn't pass his saw making knowledge to his son either, but instead told him to become a general blade maker who can make knives and plane blades. Heiji is a 5th generation saw maker, his ancestors all saw maker, going way back to late Edo period.
I can agree with both sides, Heiji-san's and Mitsukawa-san's, and I feel so lucky to have access to both of them....
Below, on the right is the forged plate for Kataba saw, right after hardening, before flattening. The left one has been flattened and thinned with sen. Because it is repeatedly hammered the steel molecule become smaller, and this means sharper teeth, tougher longer lasting edge, and easier sharpening.