This is one of two costumes I got from my stepsister when she gave me her dolls and their collections in 2009. (The other was the Sugar Plum Fairy outfit.) It was missing the mask, wrap, and bag. The remaining items seem to be in perfect shape, with no cracking on the tiara.
Personally, I think that while the dress itself isn't that bad, the tiara and wrap are kind of ugly and a bit awkward-looking. AG would do a much better mermaid costume a few years later.