I've gotten mine from www.Eluxury.com (I used to work there and got a 25% discount...I miss that!) they actually own the Dior label since they are all owned by LVMH (Louis Vuitton Moet Hennessey). I've also shopped at the Dior store in Manhasset, NY, and in Woodbury, NY there's a huge outlet center (Woodbury Commons) with a Dior store. Haven't bought one there yet, though, they have good prices.
Online, you can get Dior bags at decent prices by shopping the sales at these sites: www.saks.com - having a sale right now. www.neimanmarcus.com www.bagboutique.net - having a sale right now. www.bluefly.com - discount store...everything on sale.
I live in Newcastle(England), about 5 hours away for a dior...so official UK website for me! Yea i wish that there was one closer, but i love receiving those boxes in the post
I got 2 of my Diors from the Honolulu boutique when i was there on vacation last Christmas, and my bf got me one from Harrods in London, and he also got me another from ebay.