Hopefully some other LLL collectors can come on and either agree or disagree with me but I'm going to say $5-$8 for this dress in the condition yours is in.
Yours looks like it is in good condition with no snags on the sleeves, the pixie petals look great, the ribbons look vibant and not fraying, it isn't stained or discolored, and the pink parts looks nice and crisp still.