I guess I'm like most others here, I don't have a "collection" so to speak, but have quite a few. Most of mine are gifts, and I only shell out the $$$ if it's unique. My quest is usually to find one in a unique color, not black. My favorite one is at least 15 years old, and it gets worn the most. (you can almost see thru it now....lol)
I also have a couple of polo's and button downs.
A few years back, I read an article in Hogtales that suggested you only buy one from a shop if you ride to it. Kinda hard to do though if you travel alot.