I didn't pay much for the portrait I was happy enough to find on e-bay earlier this year. They appear to be of about the same size. But I may just have been lucky. The ebay seller didn't know who Kajiwara was.
I think it is typical of studio portrait photographers. Even if you were pretty big and popular in the your own time, the family portrait don't have much economically value a generation later, or two or three, when the people on the images are forgotten. But I value my portrait very highly. I may swap it for a SMC Pentax-FA* 200mm macro lens, but nothing less
And I like to congratulate you for finding it! And thank you for sharing it here!
About the lens-naming etc that you also mention on your blog. Takuma himself says in an interview that Takuma means to polish or grind, like when they make optical lenses. Based on this, I think it was a sort of linguistic little game of his niece (Pentax boss at that time) to name the lenses Takumar, and of course honoring his uncle.
I still hope that we will be able to locate some of his more artistic and experimental painting (and larger photographs from exhibitions). They ought to be in storage at some US museums. Or perhaps owned by his Japanese family or descendants of his wifes US familly. I wonder what they may be worth?
Edit: Very nice that you managed to find something out about the woman on the portrait!