What’s your favorite easy flip that surprised you?

I just had a great experience with a set of vintage mugs I picked up at a yard sale for like $3. I honestly thought they were just cute and wouldn’t sell for much, but after looking them up I discovered they were collectible! Ended up selling them for $30 within a week. It’s always a thrill when you find something that surprises you like that! What’s your favorite unexpected flip?