Judging by the sheer volume of Christmas decorations that flood stores at this time of year, it would appear that many people don't merely replace the odd tired or broken ornament, but completely overhaul the look of their trees and homes each year. But I think there's something to be said for keeping new purchases to an absolute  minimum, for reusing the same old decorations as much as possible: It's so the children can exclaim, "I remember this, we bought this when I was three," or "Remember this? This is mum's favourite."