"Any sufficiently advanced technology is indistinguishable from magic," said legendary science fiction author Arthur C. Clarke. Store shelves today are brimming with downright magical devices, and many of them are selling for a song. 

From Apple's (NASDAQ:AAPL) unique set-top box to Skullcandy's (NASDAQ:SKUL) smart headphones and Logitech's (NASDAQ:LOGI) powerful twist on the universal remote control, consumers have their pick of inexpensive high-tech wizardry. And for the more hard-core tech heads among us, there's a variety of low-cost computer systems just screaming for a programmer and a soldering iron.

Any of these items would qualify as "magic" to many people -- and all for a bargain. On that note, here are five gadgets under $100 that will blow your mind.

An Android smartphone controlling the Logitech Harmony Home Hub. Image source: Logitech.

Sam Mattera (Logitech Harmony Home Hub): At $99.99, the Logitech Harmony Home Hub just barely makes the cut, but it's a device that deserves a spot in virtually every living room.

In an era of cable boxes, audio receivers, game consoles, and streaming set-top boxes, controlling the TV can be a difficult, and at times confusing, process, involving perhaps a half-dozen different remotes. The Harmony Hub replaces all of these remotes, delivering a clutter-free coffee table.

Using a combination of Bluetooth, Wi-Fi, and radio-frequency blasters, the Harmony Hub can control as many as eight different home theater devices, even ones tucked behind cabinet doors, as well as a variety of different smart home gadgets.

The Hub can be controlled with nearly any smartphone or tablet, or for an additional $30, users can buy a single, standard universal remote control. The Hub can learn specific tasks -- watch TV, play Xbox -- and with the push of a single button, automatically turn the proper components on or off and adjust the inputs automatically.

Logitech has been a solid stock to own over the last two years, crushing the S&P 500 even as the slowly declining PC market weighs on its core mouse and keyboard business. As a way to simplify the living room, the Harmony Hub could be an equally wise investment.

Tired of iPods? This Raspberry Pi powers a fully functional Internet radio system. Image source: the Raspberry Pi Foundation.

Anders Bylund (Raspberry Pi): Raspberry Pi is more than just a deliciously geeky pun. It's also a family of crazy cheap computers that fit in the palm of your hand. Priced from $20 to $35 per system, these little breadboards pack a serious computing punch.

The Pi isn't exactly pretty, and it's far from ready to run right out of the box. But the $35 version (let me splurge on this example!) comes with a quad-core 900-Mhz ARM (NASDAQ:ARMH) processor built by Broadcom (NASDAQ: BRCM). It has four USB ports and a programmable 40-pin connection array, next to a high-speed Ethernet port and a full set of audio and video outputs.

If that sounded like a Greek lunch menu, I'm afraid you should probably just move on to the next low-cost gadget on our list. But for the right target audience, the Raspberry Pi is the best thing since sliced toast.

With one of these, a soldering iron, a bucket of electronics components, and a few hours to kill, the Raspberry Pi is the perfect way for engineering students or curious adults to kill a few hours. It's also perfectly poised to put processing power in the developing world, either by itself or by inspiring a slew of copycats.

It can process high-definition video or manage network security. You can play games on a Pi, build your own wearable computing getup, or send it to space on a weather balloon to collect data (or just take pretty pictures). The sky is the limit, and for a rock-bottom price.

At the very least, the Raspberry Pi provides a blueprint for larger electronics manufacturers to follow. It's almost as if ARM and Broadcom had designed it as a marketing platform, with a very specific demographic in mind -- the makers and the tinkerers of the world.

The Skullcandy Grind is ready to rock your world. Image source: Skullcandy.

Dan Caplinger (Skullcandy Grind): Headphones have turned into big business lately, with companies like Skullcandy seeking to make a name for themselves and tap into the demand to listen to music and take calls on popular mobile devices. The Skullcandy Grind headphone set retails for about $60, but it combines solid sound and an attractive design with lightweight comfort.

The key feature for the Grind headset, though, is its ability to let you switch back and forth between listening to music and taking phone calls on your mobile device. With the touch of a button, you can pause, change tracks, or answer a call. The Skullcandy Grind also includes a built-in microphone that you can use to talk without having to touch your handset. In addition, Skullcandy knows how easy it is for headphone cables to get twisted or cut, and so it has a detachable cable that you can store separately in order to keep it safe and prevent wear and tear.

As an investment, Skullcandy hasn't turned its business acumen into a shareholder success story, with the stock recently losing almost a third of its value. But with an eye toward affordable gear, Skullcandy's products turn heads.

This Timing Power RK3188 Android Mini PC combines deceptive power with sleek style. Image source: Timing Power.

Daniel B. Kline (Computing sticks): Improving technology has redefined the definition of portability when it comes to computers. Portable used to mean laptops (and way back in the day, lugging around the early Apple Macs). Now, portable encompasses form factors ranging widely from tablets to hybrids to other tweener devices. The most interesting of these, however, might be the computing sticks

Under $100 gets you a full-powered computer the size of a fat flash memory stick. To stay within a $100 budget, you'll have to settle for a stick running Google (NASDAQ:GOOG)(NASDAQ:GOOGL) Chrome OS or Android; those running Microsoft (NASDAQ:MSFT) Windows cost closer to $200. For that price, however, you'll get a mini-computer that fits in your pocket. Simply plug it into a HDMI slot on a TV or computer monitor, add a keyboard and mouse, and you're good to go.

This has the potential to change the computing equation for travelers and businesspeople alike. It also lowers the price point for full-powered computing devices to the point at which a computer with a familiar Chrome or Android interface is affordable to a much larger population. Computing sticks are not Raspberry Pi cheap, but they are accessible and should be popular specifically among people whose first connected device is an Android phone.

Apple TV is a uniquely talented living room hub. Image source: Apple.

Keith Noonan (Apple TV): Priced at $69, Apple TV isn't the cheapest set-top box on the market. Depending on what you're looking for, it also might not offer the best functionality. When stacked against competing devices such as the Amazon.com Fire TV Stick, the Roku line, or even Google's $35 Chromecast, the Apple TV offers comparatively little in the way of gaming features.

But it makes up for its deficiencies with other key content.

The tiny device is currently the only set-top box to feature the $15 a month HBO Now channel, an over-the-top offering from Time Warner that allows subscribers to access some of the hottest shows on the market. For prospective cord-cutters wary of losing out on water cooler discussion pieces like Game of Thrones, Silicon Valley, and True Detective, the Apple TV plus HBO Now combo could be a major money saver over time. Throw in a Netflix subscription and you'd have access to a wealth of content and still be looking at a monthly bill well below that of the average cable service.

Apple TV also allows you to stream audio and video to your television from your Apple mobile device or laptop via AirPlay, a key feature not replicated by the Chromecast. So while less expensive set-top options are available, Apple TV might offer the best value for users already steeped in the company's ecosystem.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.