I've seen the VB bags at the DLH gift shop, in WOD in DtD, possibly in the GCH gift shop, in Vault 28 in DtD and in Disney Clothiers on Main Street. Elias and Co. in DCA might sell them, too. If you are particular about pattern placement, then I would buy in the parks so that you can actually choose the bag to buy. Otherwise, I've had very good luck buying VB things from DisneyStore.com. The bags arrive wrapped in plastic, so I know they haven't been mussed or picked over. The bags do go on sale sometimes, so if the sale price is lower than I could get in the parks, I'll buy from DisneyStore.com and look for a free shipping coupon code, too.
You can get them on eBay as well, especially if there's an older print that is no longer available in the parks. I got mine for half price and it still had the tags on it!
Thanks, everyone! We'll be at DL in September. Excited to check out what they have in the parks. I wanna get one for myself and a couple of little purses for my girls as Christmas gifts!
I like to buy mine in person because I like to choose the pattern placement, especially if there are characters on the bag, not just the Mickey head silhouettes. I bought my hipster at WoD.