If you can get a knife at a good price that will do what you want, then why not. If you're into the 4 inch scandi ground stereotype 'bushcraft knife' a mora or hultafors will do just fine. In fact, the vast majority of us carry one in a pack as a spare if going out for any real length of time. If you're bumbling in the woods for a day or two, it doesn't matter if they break or don't keep an edge for the longest time, you'll get by. You might even upgrade to some full-tang beast if you are tough on your knives, or beat them through logs, but it still won't break the bank.
However, if you want something that is made just for you, something you can really rely on, you probably need to spend a bit more money whether it's a higher end factory-made knife or a truly custom blade. Top end factory knives like Spyderco command high prices because you are getting a precision made knife with some of the finest materials available, backed up by research, with a warranty and with edges that last nearly indefinitely. I don't mind spending a hundred odd quid on one of their folders. I always have my PM2 in my pocket. It's perfectly made, comfortable, ergonomical, a no frills tool that's always sharp - I basically never have to sharpen it.
However, if going down the custom route, I can honestly say you could waste a lot of money, very quickly. I'm not really interested in paying inflated prices for a knife that is basically ground out of stock steel, much the same as a good factory knife. You know the one's I mean without me having to say. However, I will pay hundreds, maybe even four figures for something special, maybe a hand-forged blade by a master bladesmith with a fine handmade sheath to go with it and not regret it one bit. I appreciate the time that goes in, the skill required and that the finished product is something I couldn't get anywhere else. Something that is perfectly formed and guaranteed to do exactly what you want for as long as you want. Of course, you can spend a bit of extra money on an ornate handle to make it a bit nicer looking, and if you're going this far, I see no problem with adding a few quid to fulfil your desire for an aesthetically pleasing knife while you're at it. We do the same with all our kit, bags, clothes etc.
It's probably easier for me to justify stuff like this as a craftsperson of high-end leather and canvas goods. I understand what goes in to things like this. I work with customers to make sure they get exactly what they want and it is entirely handmade, and something that can't be bought elsewhere.
Basically, If I'm going somewhere remote, I'll bring my hand-forged camp bowie. It will never let me down, the smith who made it demonstrates that his knives will do more than almost any others with regular testing. I don't care how much it costs, I'll limb a tree with it, clean fish and game, prepare my dinner, defend myself if I have to. Someone did ask me recently, 'what would you do if you dropped it', knowing it was worth a few quid. I said I'd pick it back up again