Free should only trump everything if the item is close to perfect or gently used. (perhaps that was not mentioned because it’s an understood fact?)

Getting a free, used keyboard is a great idea. The keys on a keyboard are fairly standard (action not withstanding), so if you find you lose interest in the hobby, nothing lost!

Get knives that are non-serrated (for general purposes, unless you are talking about a bread knife) and the metal on them should not generally and you will likely be headed in the right direction and you will in most cases get a knife that is decently serviceable if you also have a means of touching up the edge.

a $50 combination Shun japanese waterston, 300/1000 grit is what I use for most sharpening. I use the 300 grit (there are actually coarser grits available but I don’t see the need for one in my own life) on heavily abused blades in order to restore the geometry, followed by the 1000 grit to bring it to near razor sharpness, followed by stropping on a piece of newsprint laid across the stone for full raxor sharpness (cardboard words too.)

There’s no doubt that there is both an art and science to sharpening, and that it does take some investment of time and effort and study.

For most people, a Cutco pull-through sharpener works fine. It won’t restore a truly neglected blade but it does a good job on most blades without the user needing to totally understand what he/she is trying to accomplish.

If you really want to learn to sharpen, I recommend Murray Carter’s DVD about it.

With knives, I’ve gotten several for free. All I ever do is end up giving them away (or trashing them). I don’t buy super pricey knives, but I do buy decent, solid knives that hold an edge. To me, it’s worth it to spend $30-50 on a knife rather than constantly curse a dull one and worry about cutting myself.

A better place to make this argument, it would seem, are in things where a little quality might not make a difference. For example, with textbooks, I frequently buy used because it really doesn’t matter if there are a few notes or highlights in the book; it won’t affect my experience. Or with my new cross-country skiis. I did buy new skiis, but I bought low-end, recreational ones. I could have spent more to get really nice, fancy skiis. But even though I ski about once a week in the winter, I never ski for speed or performance. I just like getting out, enjoy the woods, and having some exercise. For me, the $250 pair I bought are good enough.

I think part of it is that just reading through, Trent’s conclusions don’t really seem to fit his experience. He gives examples of three types of knives: almost-free/middle/pricey and then even though in his own analysis the middle one is clearly the best value, he dismisses it from his conclusion and even ignores it in the question itself and just says ‘free is better than expensive’.

It’s just weird.

Anyway, first of all, I’m not even sure what “argument” you’re talking about. All people are doing is pointing out that Trent’s statement that “the worst thing that can possibly happen is you lose 50 cents” is not true.
Second, knife sharpeners are not free. There are cheap ones that you can get for a few bucks, but there are also ones that run into the $100+ range. So the total cost of a 50-cent knife plus a knife sharpener is more than 50 cents. And if you’re buying a knife plus a knife sharpener, then you have two items for which you have to figure out the relationship between cost and quality, not just one.
Third, as Steve in W MA notes, “just sharpen the knife when it needs sharpening” requires that you know how to tell when the knife needs sharpening, which not everybody does.

Again, I’m not saying that everybody needs to be buying $100 knives – just that the tradeoff between low-end and high-end items is not nearly as clear cut (pun intended) as Trent’s making it out to be.

I really don’t get all of the hubbub over the $0.50 knife being dull? Trent never advocated buying the knife *and never sharpening it*! Seriously, folks! A knife sharpener is not a big-ticket item! A $0.50 knife can–and should–be sharpened!

Then…once it’s been sharpened…what exactly is wrong with it? (Other than the fact that your argument disappears.) If it needs sharpening every two months because it is a weaker metal…well, then sharpen it again! :) Not rocket science!

Here’s another example: wiring your speakers on your hi-fi setup with ordinary lamp cord versus fancy-schmancy Monster (or similar) premium cables. You can pay a buck or two, or … well, it’s possible to pay thousands of dollars for several feet of speaker wire. (Really!) I’d be surprised if one person in 10,000 could actually tell the difference, if the test was set up correctly.

With musical instruments, it’s a little different: I rented a saxophone once, a cheapie, and it was badly designed and physically hard to play (key leverage design and spring tension were awful). The physical uncomfortableness of bad design would have been enough to drive many potential musicians away. That’s a situation where you need to either know the universe you’re buying into, or know someone (e.g. a professional musician) who does. The horn I’m playing now is a classic that cost me a little over a thousand bucks (a hefty taste, a while back) but it was such an ergonomic joy to play that it made practicing something to look forward to.

I bought my very nice upright piano for $5500, and I am pleased as punch with it. I have never, ever played an electric piano that comes even faintly close.