By paying the big bucks, most of the time you will get the best but there are the exceptions out there. Have a look around, play with some demo models in the shop and learn what you are buying. Just because the unit is really cheap doesn't mean it's going to last a week, just because it cost more than the average family home doesn't mean it's going to last forever. When buying a headunit, don't be afraid of the cheap car stereo on the market but do research it first.