bm dress question

I have a never been worn or even altered bm dress from a wedding I was supposed to be in but it got cancelled and we arent friends anymore....I wanted to donate or sell the dress but dont know where to begin, anyone have any ideas please let me know!

Thank you!

i know St. Brigids church in westbury has an 'attic store' and they have a bunch of dresses that they have for kids for proms and stuff???

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