Cost all of around $40, is a genuine joy to use, and keeps all of my knives sharper-than-sharp.
I started out with a very expensive knife (Wusthof classic 8", around US$150 or so at the time) but nothing to sharpen it with, and this was a mistake.
If I could do it again I'd recommend young cooks on a budget start out with a $20 IKEA knife and a stone to keep it sharp. You'll get better long term results than you would with an expensive knife on its own any day of the week.