I recently wore a long gown that I had purchased several years ago.  As long as I keep my weight within a few pounds up or down range, I am able to wear clothes for a number of years.  The interesting thing is that they don't seem to be "dated."  This particular dress I recently wore received a number of compliments - as if I had just purchased it!  I find that when something fits well it can sail through several wearings.  I've used a philosophy for several years that if something is coming home, it had better be more outstanding that what I already have in the closet.  And if it does make it to the closet, then something must go out of the closet.  This has created a healthy flow and leaves me with what I call a "magic closet" because I can recombine items and always have a fresh look, regardless of the age of the item.   While I do try to stay with a contemporary look, I also hold onto those items of clothing that fit well and make me feel great when I put them on, regardless of their age.