There's that and the fact that while you do hear this advice a lot, chef's (at least ones that actually cook) and busy line cooks typically walk into work with a knife case. It isn't filled with $20 knives. If you're using a tool for many hours a day, it pays to have a really nice tool. Even if it's only marginally nicer, that margin adds up. (It may never add up for the home cook, but that's another debate.)

But if you're making an order to fill out your kitchen, it's no surprise the cheap but fully functional knives will be ordered. $20 * 10 is a lot easier to justify than $100 * 10.

Okay, folks, you drove me to the books -- or rather to the Cooks Illustrated website, which no self respecting geek who cooks should fail to subscribe to. They ran lots of knives through tests and recommended the Forschner Victorinox Fibrox Chef's Knife, which cost $25.33 in 2005.

So, I lied. You might not want to use a $20 knife. You shouldn't spend a penny less than $26. ;)

Note that this is a brand-name product. Wouldn't be surprised to see the no-brand version at a supply store for $19.

Note also that knives are a personal thing. If the cheap one doesn't fit your hand you'll want a more expensive one. C'est la vie.

It's true that keeping your knife sharp is really important. Unfortunately, you can dull an expensive knife as easily as a $25 knife. You should get a steel and try to figure out how to use it. You should get your knife sharpened when you sense it's getting dull, or you'll injure yourself. You should use the right cutting board. You should have a knife that's all your own and hide it from other people, lest they smash the edge into a solid metal object. You should watch Alton Brown's show about knives to learn these things.

Mr. Brown recommends pro sharpening because he thinks all the homegrown solutions suck by comparison. Cook's Illustrated, OTOH, recommends the $80 Chef's Choice 110 electric home sharpener, which you can afford with the money you saved on that $110 chef's knife.

Pro chefs carry more than one knife, in a case. You also need more than one, but not many more. In his book, Anthony Bourdain (famous pro chef) recommended a chef's knife, a flexible boning knife, a paring knife, and an offset serrated knife. Alton Brown (famous geek pro chef) also suggests kitchen shears and a 4 to 5 inch utility knife. Cook's Illustrated suggests that you might want a slicing knife if you carve a lot of roasts (alas, I don't; I married a vegetarian), or a cleaver if you often make homemade chicken stock (see above).

You'll also need some steak knives if you're not married to a vegetarian like I am. ;)

I'm not sure it's possible to put $100 worth of value into a knife. It would have to be rare isotopes of iron and carbon...no, I just don't see it. I mean, they're commodities. Paying $100 for a knife is like paying $30 for a gallon of gas. Why would you?

Think about it: a kilo of steel is roughly 75 cents. A pound of plastic is less than that. I'm not being exact (commodity prices are hard to find online), but they are both >> than $25, which seems to be the consensus on the best you can get for a knife. And from an industrial point of view, it's really not that hard to assemble a knife. I don't see where the money goes. Maybe the handle?

Besides, if you pay $100 for a knife, that means you are a) a squanderer, b) gullible, and c) someone who overestimates the returns of investing in cutlery. Wouldn't a boxcutter do? These traits are not entrepreneurial. I wouldn't fund you. Maybe I'm a little extreme (I have a really hard time paying an extra $.04 per can for significantly less unedible tuna) but I'm pretty sure $100 per knife is retarded.

Chefs don't have lackeys to sharpen their knives every night. $100 knives are vanity items. Working chefs all buy $20-$30 knives. Celebrity chefs have $200 knives because they get them for free.