Knives are weird. You can spend $3 or $300 on one that looks the same as the other.
Like most boys and outdoors people I love a good looking knife, but I'm about 30 years past the "Ego" part of the purchase.
We bought a relatively expensive Cutco kitchen set 12 years ago from my niece and they're nice, but the best thing is that we can send them back to be replaced or sharpened.
I'm not really sure the actual engineering or properties of the knives are special.
I know there're different metals and ways to grind the edge. Anyone know what really makes a $300 knife worth it ? Thanks.
Chip, it's a huge subject and fascinating. I'll try to be brief so feel to ask follow ups.
Short version, to paraphrase Pirsig, a quality knife is one that gives you peace of mind.
More concretely, the knife should do the tasks you need it to do and should make you happy when doing it. Form follows function so the first step is to get specific about what you want to do that might need a knife. Ultralight backpacking, every day carry (EDC), general outdoor use, woodcraft/bushcraft, hunting, working in the trades... all of these put different demands on a knife.
Not knowing what you want to do and thinking that you might not want to read a long post by a knife knut, I'll just make some specific recommendations right up front. For ultra lite hiking, I like the Leatherman PS2 Squirt. Handles most repair jobs and 1st aid needs just fine. If you need a larger knife for food preparation, I would recommend either the Opinel #8 Inox Stainless (or #9 if you have big hands like me) or the Ontario Rat 2. If you feel you need a fixed blade, I would recommend the Mora Companion Stainless version. None of these knives will cost more than $30 and all are very solid knives.
But, you asked about $300 knives so now we get into more details...
Fit & Finish - Knives can be works of functional art that you can carry with you. As you move up in price, you start getting into either custom made or super high tollerance manufacturing. I like inexpensive but high quality knives and I drive a Subaru. But I don't begrudge people for liking their Lexus quality knives. Here is a video comparing a $300 Bark River knife to a $20 Mora.
http://youtu.be/sLlxWbce4iE
Blade Grind - Refers to the shape of the blade in its cross section. This has nothing to do with quality but has everything to do with matching the design to the task. Here's a primer.
http://en.m.wikipedia.org/wiki/Grind#Typical_grinds
Hollow grinds are popular for hunting since the super thin edge cuts meat well since the meat self seperates. Scandi or Sabre grinds are popular for bushcrafting since they split wood well when you baton. Convex grinds are popular among some bushcrafters. Flat grind slice vegetables well and many consider them to be the best all around shape. I strongly prefer convex ground blades (Opinel) but like flat just fine too. I like sabre grinds ok but usually convex them for better wood working. I don't like hollow grinds at all except for hunting knives.
Lock and Joints - A folding knife is tricky. IMO, any folding knife will close at the worst possible instant. I never fully trust a folding knife and won't pry with them. I'm much more interested that a knife won't develop vertical or lateral play under hard cutting. I like lock back designs for hunting or casual EDC but I find they develop play under hard use. I can live with liner locks or frame locks but never rely on them staying open. The Opinel is among the toughest folder I've ever used. Traditional slip joints and lockbacks that rely on peened pins are beautiful but can develop lateral play.
Steel - We could talk for hours and hours about steel. I'm going to very, very crudely summarize and say there are basically 2 kinds of steel. Fine carbide steels are sort of like cement made with sand. Large carbide steel are sort of like concrete with big bits of hard gravel in them. Large carbide steels are very abrasion resistant so the edge lasts a long time. In essence, the big carbides are rough and keep cutting well as the edges wears, especially in fibruous materials like rope. The downside is that large carbide steels can be harder to sharpen, unless you know how to sharpen and have really good stones. Fine carbide steels are generally very tough (they don't chip when abused), take a very keen edge and are easier to sharpen (especially when starting out).
For starting, I would recommend sticking with fine carbide steels. They include (among others): carbon steel/1095, carbon CV, 420HC stainless, 440A stainless, Aus 6 and Aus 8, Sandvik 12C27 (Opinel, Mora).
The other thing to know about steel is that it must be tempered, or heat treated, by the knife maker. Knife makers get "raw" steel from the manufacturer, cut it and shape it and then do their heat treat. Generally harder is better in terms of heat treatment but this depends entirely on the knife maker, not the steel. For example, Case and Buck both use 420HC and Buck does a much better job heat treating it. The knives I recommended above all do a great job with their heat treat.
The newer high carbide steels get very expensive very fast. Are they better? Not if you can't sharpen them they aren't.
Sharpening - There is sharpening and then there is sharpening. If you've not sharpened before, my recommendation is to get a Lansky guided rod system. If you plan on getting expensive steels, get the diamon hones. This will teach you how to raise a burr, which is the secret to sharpening. Once you get the hang of it, you can touch up blades with a pocket stone, like the DMT credit card stone in medium or fine. Do the heavy sharpening on teh Lansky. An alternative to the pocket stone for quick touch ups is something like the Spyderco Sharpmaker but this makes more sense to me for people like Chefs.
FWIW, this is what I carry when hiking...
Outdoor Carry by
Pinnah, on Flickr
I like to think I do. FWIW I don't like folding knives. For blade length - anything below 3 inches seems too small for me but as I said I don't really need a knife to begin with. 
