Unsurprisingly, Etsy seller Maisy Brown's pretty tuxedo dresses are some of her bestsellers. A very cute take on the ever-popular mini prom dress, this has the added bonus of being custom made to fit your measurements. For that, I think it's worth every penny of the $225 price (though that does sadly make it ineligible for my 100 Cheap Party Dresses feature). There's also one in a US 6 - 8 going for $210 if you need it quickly, though I know I wouldn't be able to resist the pull of something made specifically for my shape.
Don't forget to check out Maisy's blog, too, if only to see how she can turn a tablecloth into an amazing frock!
