It is very important to look at the construction of the cabinet box.  Most cabinets come standard with a particle board box.  You will pay at least 10% premium for the a plywood box.  All of our cabinets cabinets come standard with a furniture grade plywood box. 

The problem with particle board is does not hold a screw as well as plywood and the biggest problem is when particle board gets wet it swells up.  Here is a link to Consumer Reports on what to look for in a quality cabinet.