Kristy is in the market for a new laptop. Does she need an i7 or will an i5 do? Leo says that an i7 has more cache and has hyperthreading, but that's really only beneficial for video editing or gaming. Average daily use doesn't really need all that, so an i5 will do just fine.
In fact, she can take that extra money and get a nice external LCD screen that will allow her to improve productivity. She should spend money in areas that will benefit her most. If she's going to get a laptop, as Kristy is, she should get a fourth-generation Haswell chip. It'll double her battery life. She won't find those at a big box store though.
She should also go for a Solid State Drive. It's much faster, but smaller too at 256GB for instance. 8GB of RAM is a good idea too. If it's Windows 8, she should look for a computer with a touch screen.