As a single woman living in an increasingly pricey city, buying used is a great way to get like-new items at a fraction of the cost. However, the used economy still presents an element of risk. I've definitely encountered my share of creepy situations in the past. (Case and point: the strange man I interacted with on Craigslist who seemed more interested in "getting to know me" than purchasing my old couch.) No sale is worth compromising your personal safety. Here's a few safety tips to follow when buying and selling online.