I agree for most things. For laptops, however, buying new does not mean it will be good quality and you will have no problems I had many problems with an expensive HP 17'', and now with a Samsung netbook
Warranty? Well, they change the wrong component by a new one but which presents the same defect, sometimes they change it three times, until the warranty period is over, and then, too bad for you, get a new one!

Sometimes it's also a great pleasure to buy new (a car for instance) even though it is a total waste of money