We've struggled getting a Tiana one too, Disney Store has been waiting for new stock for ages they've had a couple of dresses but all been aged 7-8 and the ones on ebay have been going silly
we went for a new Rosetta one in the end this weekend, I sold it to dd saying 'oooooh this ones nice and short not like Tiana so you could where this one out to the parks in the day!' instant sale
I agree - that's the best shop, full of all the princess dresses and every accessory you could imagine!! (Unless of course you're looking for a Tiana dress in which case you've had it!)
I love the Rosetta dress!! It's beautiful!!! DD really wanted Silvermist but they all went in the sale so she opted for Tinkerbell in the end.