I'm all about function and quality regardless of price or perceived value. I'll carry a $500 knife sidecar to a $15 knife. Some days I leave the house with a Kershaw Zing and a Cold Steel Tuff Lite, and some days I leave the house with a 0561BW and a EX-02.
(You'll note that I don't really tend to carry anything worth more than $200. This is where our respective incomes come into play.)
What and why is entirely up to you. There is no perfect philosophy for knife ownership that you are violating by carrying any kind or variety of knife regardless of what you can or cannot afford. I've known people personally that had basically no money whatsoever but carried very expensive knives, and I'm close friends with a guy richer than is easily relatable and he whines about spending $80 on his Manix.
It's all about what you perceive to be worth it. A quality $100 knife will probably cut just as well as a $700 custom. They might even have the same blade steel and grinds. The $700 custom will likely have more attention to detail, and, if you spent that much, probably has a lot of little aesthetic and ergonomic characteristics that you enjoy. The $100 knife can be beat on all day, stand up to it, and be sent to a manufacturer for quick-turnaround warranty service or immediate replacement.
I don't take much pride of ownership of a knife, personally. I enjoy a well-made knife, but they are cutting tools to me. I might quite like the look of a cutting tool, but I'll be damned if I'm going to carry around a sharp rolex. Just not my style. Nobody is going to be impressed except for people on the internet, and spending hundreds or thousands of dollars to impress people on the internet is basically just being an attention whore that hasn't figured out how the whore-john economic system works.
Whatever you get, get it for yourself. If your own personal enjoyment is enough, and you can afford it, you don't need to explain yourself or question it. It's what you enjoy and you can get it if you want to.