As has been noted. The Perfumed Court and Surrender to Chance have huge inventories of fragrances. However, they are very expensive and delivery charges are completely out of line( Im outside the continental U.S.). However, the Decant shop is new but is developing a good reputation in a hurry. No charge delivery with order over 50.00USD and they are quick and I did receive an extra decant free.
Also, if you are looking to more obscure and hard to find, try ALZD (First in Fragrance) A very reputable site but its a bit pricey.