Although the Mac mini is significantly less expensive than an iMac, you have to provide all peripherals and accessories. If you don't already have a screen, keyboard or mouse, you'll have to buy them to operate your Mac mini, and you might end up spending more than you would if you bought an iMac. The 2011 iMac comes with a camera, more powerful processor and hard drive, speakers, keyboard and other accessories for $1,199 [source:Apple] .
Depending on how and where you plan to use your Mac mini, you might need a mounting kit. For instance, if your Mac mini is going to be mainly used as part of a home media center, you could mount the computer on a wall or ceiling. You could also choose from a variety of Mac mini table mounts. These mounting systems will securely affix your Mac mini to the surface that you choose so that you can easily access your device and not worry about it falling and breaking. When choosing a mounting system, keep in mind that you won't want the mount to cover important ports that you frequently use.
Although the Mac mini comes with four USB ports, an extra USB hub might come in handy if you're connecting multiple devices to the computer. Once you plug in your mouse and keyboard, you've used up two ports already and you haven't added your printer or other peripherals yet, so this could be useful.
Finally, since the Mac mini does not come with an optical drive, a good accessory to have on hand is the MacBook Air SuperDrive [source: Frakes]. Although it's designed to be used with a MacBook, it's compatible to the Mac mini and is a good option if you plan to play CDs or DVDs on your computer.