As an aside, professional chefs knifes go easily for 50-100+ PER KNIFE.
Also, most people don't know how to sharpen their knives and keep it sharp... so I'll tell you how;
the steel rod isn't for sharpening the knife. It's to keep the edge straight.
Because of how thin a sharp knife edge is, repeated use has a tendency to BEND the knife edge, rather than actually breaking/dulling, at least with good knife blades that are malleable.
You use the rod to straighten out the knife edge after every 3-5 uses (not each slice but rather each item)... so basically you're supposed to keep it on hand and use it like an obsessive compulsive... depending on how sharp the knife is though (the sharper it is, the more you'll need to sharpen; 3-4 uses for the sharper angles.
To use, you basically run the rod along the angle of the cutting edge a few times, then repeat on the otherside with the same angle. Probably best to run it in one direction only.
Secondly, you'll have a whetstone or a grinding stone. With the use of the rod, you'll only have to use this very rarely; once every 6 or so months with decent knives.
The idea is to keep a consistent angle while dragging it smoothly in one direction and one motion. Drag it for the entire length of the blade, and don't push it back up; lift off and repeat at the same angle. Repeat for the other side.
With that, you're grinding the edge of the blade to a consistent angle, which is what you'll need for a good clean cut.
It might sound obvious, but some people that don't know how to use the knife would be using the sharpening stone as a file.
When you're doing that, depending on the stone, you'll want to either lubricate it with water or mineral oil. I think the water lubricated stones are called wetstones or whetstones. It should be obvious when you're shopping for it; or ask the salesman.
Finally, differing angles of sharpness have their uses; the wider angles (blunter) are useful for hard objects, such as cleaving through bones, while the finer angles can be exceptionally sharp, but also bend very easily.
If you keep your knives sharp and maintained in such a manner, expensive knife, or cheap knife, they should all serve you very well.
