Maria is looking to buy a used MacBook on Craigslist. Leo says that it's risky to buy other people's used computers because she'll be buying other people's problems. Additionally, Craigslist is the home of scammers. It can even be dangerous. Leo advises going to Apple and looking at their refurbished products. She can save a few hundred that way and she'll still get the warranty to boot. A MacBook Air is affordable, thin, and very powerful. The 13" MacBook Air is Maria's best option.