Since OP sees this more as art piece & investment...
I think this ALL depends on your wealth level. NOT at all about what the inherent or intrinsic value of an object is, but what the perceived value is. Similar to how much a painting is rather than the price of a shovel at Walmart.
For example, $20 is just chump change for most of us Americans. Is it poor investment to buy a $20 whatever...? Eh, I enjoy the collectible, It’s cool, I break it, whatever.
How about if u were dirt poor and broke as turd in Somalia. No way you can justify any knife over $100. Everyone there will say you are retarded for buying a $100 knife.
The point is, if you have enough wealth to carry $400 knife as a beater knife. You probably see a $9k investment as what most of us see as $200 investment. Expensive...?well relatively so. But most wont go broke over it.
Be happy of your abundance, appreciate the art, enjoy your wealth status of capitalism, and have fun. If someone doesnt see a $400 knife used as beater knife as sensible, they wont see a $9k knife as sensible either.