5 seconds?!
Poor assumption. You're presuming this is "only the types of cables you buy". Many times I buy cables to do things with devices, for which I have no working cable already.
Examples:
* My device stops syncing with my cable. Is it the device, or the cable? I buy a replacement cable, just in case.
Replacement cable doesn't work. Now I think it's probably the device.
I spent time here, checking to see what's changed, maybe an update, maybe a config setting, maybe something else. Or, is the device just broken? Do I send it away for repair?
* I want a cable to use with something I've had for years. Lots and lots and lots of examples here, all sorts of devices, like serial cables to debug with routers/switches, test cables, even just an ethernet cable, if you may not have had one before.
Now you test, and you can't tell. Is the port on the device bad? The settings you are using to connect? The device firmware? A problem with the port on the computer you're using to connect to the device?
Hours and hours wasted.
Worse, you advocate buying two. Great. This means that no matter what, I'm returning that spare cable. Now it's not '5 seconds' to determine it is bad, it's 'no matter what, I'm spending 20 minutes returning something I never wanted to begin with".
Frankly, I'd rather spend $10 extra on some types/classes of $20 cable, to have it pre-tested even.
The hidden information is how much quality control has gone into the manufacturing process. Seller A and seller B are both selling a cable for $10. Seller A bought thier cables for $8 because they spent a lot of time honing their manufacturing process and weeding out bad cables; the chance of getting a bad cable from them is 0.1%. Seller B bought their cables for $2, because they just went for the absolute cheapest option they could. The chance of getting a bad cable from them is basically 75%. You as someone buying it from Amazon can't tell the difference; so sellers like B make loads more money. Unscrupulous people hear about this and many more sellers like B show up. Sellers like A get frustrated and leave.
This is so incredible false, cable quality varies greatly:
- wires, gauge and material. Copper is expensive and some cheat using aluminum or Al plated copper. Gold plated terminals, tinned copper, etc.
- wire material and single/multi strand determines resistance and current rating, along with loses in the cable.
- insulation and sleeves can be made from different materials with a lot of properties, incl. max temperature, flame retardant and so on: pvc - cheap, rubber - expensive, nylon/polyamid - expensive, silicon - very expensive.
And that just touches the basics...
If the cable fails to carry a signal, or fails to do so without interference, it should be pretty easy to determine this. Failure to do this would make it "faulty".
Sure there is: How well a cable handles being bent, and whether or not it catches fire... Cables and especially chargers are some of the products I'm most cautious about buying from sellers I'm not confident about exactly for that reason.
(not that origin is sufficient - the one charger I have had that got closest to setting the house on fire was a genuine Apple charger [many many years ago, they had a design flaw with a too-short sleeve on the cable on the early Macbook chargers; it'd bend and short and melt])
Akerlöf doesn't seem to apply here, there's no hidden information that comes out later. With a car there's all sorts of dimensions to it that might annoy you.
Perhaps the idea is that all cables will go to crap eventually, but my detection cost is also fairly low on that. Additionally, and this is probably not a great dynamic, I can go to the website of a box-store, which will carry some of the same brands, presumeably vetted more than the junk shop.