Not just knives, I happen to use ALL my most expensive crap!
My working tools are Snap on / Mac / matco, my home tools (still a VERY extensive set of tools filling a 54" box) are mostly craftsman with doubles of doubles of my pro brands mixed in to make full sets where needed.
My laptop I carry with me in my work rig is my best / most expensive computer I own, at home I use a black Friday special Dell.
Note everything I'm listing here is self bought (but i have plenty of high-end work supplied tools too).
I have my best most capable stick / TIG welder on my rig, at home I have a Lincoln 120v MIG.
My most expensive knives are my custom hard use / working fixed blades and HELL YES I carry them, that's literally the number one reason I spend my money on them, not cause they're pretty or because one day they'll go up in value (though with some of them that's a very real possibility) but because I want to use them to better do my job!