6. Evening Dresses
In fashion, what was once old is new again, and younger generations love the retro styles of the yesteryears. If you had an impressive wardrobe in your day and kept your favorite dresses, you can sell your old collection for a nice sum on sites like Etsy and eBay. On Etsy, dresses from the '50s and '60s sell for up to $300, so start rummaging through that old collection!