Couple of problems associated wh the ceramic knives. Firstly; while they seem to retain a good edge longer than a steel blade, they will require sharpening. Most better (read more expensive) ceramic knives will want you to return the blade to the manufacturer for sharpening... often at their cost. Just too inconvenient, seems to me.
Secondly, if you do choose to sharpen your own, you'll need a diamond sharpening stone. A plain, flat stone at least 6 inches by 2 inches here in the U.S. can be purchased for around $12, while better and bigger ones run up to $200. The flat stone requires you have a skill at holding the blade at the proper angle.
A diamond sharpener built with angle guides can run in excess of $200.
Lastly, you'll need to know that Asian made blades (and there are some good ones) have a blade angle of 15 degrees, while the Western ones (at least here in the U.S.) have an angle of 20 degrees. One needs to know this in order to produce the best sharpened blade in the neighborhood...