Why are some knife sharpeners more expensive?

Their features, functions , and benefits. Also where they were made, who made them and any warranty.

I would stay away from all the knife sharpeners.

The only way to keep a knife sharp - is don't let it get blunt.

Get a good steel sharpener and use it to go over the knife few times every time you wash it - make it as a habit.

Most of the sharpeners - when you use them, will produce sparks, and as soon as you get sparks means that you just overheated the blade and - congratulations - the knife's edge lost its hardness.

The rest of the sharpeners will create a small boar ( microscopic ) on the knife edge and this what will be cutting, but it will brake very easily and knife will be blunt.

-------------

Learning how to use steel is very easy and you will not look back

First just use the weight of the knife - do not apply pressure

Then use black marker and draw a line on the knife's edge and see if you can rub it off using the steel. practice for 20 min and you will be an expert.

Strokes needs to be one way, its your preference towards you or away, ( i prefer away from my hand )

Good luck

The ability to sharpen knifes for years.

Probably where they were made.