If you visit an Apple retail store, you can't help but notice how every component they sell is designed to look great together. Every Mac desktop is paired with a matching monitor, keyboard, mouse and speakers. Even the adapters and cables are shaped and colored to complement the Apple aesthetic.
While matching peripherals and accessories might help you feel good about your purchase, don't believe the myth that you're better off purchasing them. If the accessory uses USB, WiFi or Bluetooth, you have a lot of non-Apple options on the market since these are industry-standard ways to connect devices.
For instance, the Apple Magic Mouse is a wireless mouse using Bluetooth and powered by two AA batteries. Besides having proprietary Multi-Touch that resembles the MacBook touchpad, it's just a wireless mouse that will set you back $69. By comparison, a Logitech V470 Cordless Laser Mouse for Bluetooth retails for $49.99, and Logitech and its retailers across the U.S. often offer discounts of $10 or more for this product [sources: Apple, Logitech].
If the accessory requires a proprietary connector, you may need an adapter, but you might not need to buy the accessory itself. For example, a current MacBook offers a Mini DisplayPort (MiniDP) for connecting to a separate display. If you use a non-Apple display with an industry standard technology, like DVI or VGA, you'll need to purchase an adapter from Apple to switch between connectors. An adapter will cost around $29 [sources: Apple, Apple].
As a disclaimer, though, we should note that some accessories offer little or no reliable alternatives. For example, MacBooks use a proprietary MagSafe power adapter, and it's staunchly defended its exclusive rights to produce MagSafe adapters. You could purchase a MagSafe knock-off, but that's risky. If the power adapter doesn't work properly, it could cause serious damage your computer that might not be covered under warranty [source: Apple].
Now let's look at a myth that's caused a lot of hesitation for prospective iPhone buyers.