OK so, if you are comfortable try looking at base quality. You may not be a very physically construction type of person but I assume you can tell the difference in some construction methods and materials.
There are some basic rules to remember.
1 Screws are generally better than staples. Cabinets and fixtures how are they held together.
2. Real wood is better than Plywood and plywood is better than particle board.
3. Stuff that appears to be solid, should FEEL solid. Things made to move should move.
These three basic rules encompass the majority of problems. New or used it doesnt matter other than on the roof, they apply. Appliances are going to perform whatever function they are designed to, generally for about 5 years with minimal maintenance, then 3-5 more years with maintenance and then they will need serious maintenance or replacement.
Its not that different than anything else in life, its your attention to detail that will make the biggest difference.
