I love vintage clothes, really I do. But, too often, "vintage" is taken to mean "anything I don't remember seeing on Friends." Some 80's might pass for vintage, but it's a slippery slope.
There are a LOT of polyester 80's dresses around. For one thing, like the cockroach, polyester just survives. For another, it's cheap and there were a lot of these lovelies made. But go to a "vintage store" in NYC and they'll have hundreds of stained Dynasty-era poly dresses lined up like so many $180 precious jewels, as if you can't just go to Goodwill and get a probably cuter one for $6.
The picture on the left, which I'm sorry to say I stole off the internet, is a prime example of these frumpy and terrible dresses that Ferris Beuller's seceretary totally wore. Guess what? They're wildly unflattering. They're not well-made. They're not unique. They were originally made for old ladies for a reason: once your boobs have reached your waist, you might as well accentuate that. The girl on the left, I'm sure, doesn't have the bod of an 80-year old. But with this shape dress, she is fast on her way to achieving it. Look, I know it's trendy to wear a "vintage" dress with your "slouch" boots and maybe "belt it" somewhere along the way, but guess what: that doesn't make it okay. You're going to look back on pictures of yourself and wonder why you spent your youth in a high-necked sack. Mark my words.