Don't you hate it when you find the fragrance of your dreams, and then suddenly it's nowhere to be found? This has happened to me on at least two occasions, but often, the fragrance isn't discontinued. Usually, it's just sold overseas or in limited batches, and if you look hard, you can still get your fragrance fix.
One great resource: the online perfume store called Parfumelle. Admittedly, this web site is pretty ugly and very user unfriendly: It's hard to browse, and not every product has an accompanying photos. But it's worth the hassle, because Parfumelle's treasure trove of hard-to-find scents is so fantastic. I found an obscure women's fragrance I've been searching for for years, as well as my favorite men's cologne, which seems to be getting phased out. I highly recommend it.