You know the old saying: if it sounds too good to be true, it probably is.

For example, yesterday I received a PR pitch from Jabra, which is offering a $15 Amazon MP3 credit when you buy the Jabra Clipper Bluetooth stereo headset -- in your choice of four colors -- for $59.99.

Here's the funny part: there's a fifth color, black, that sells for $39.99 -- right there on the same Amazon product page. I'm no math whiz, but that plus $15 works out to less than $59.99.

This got me to thinking about other "deals" that aren't. Though it's easy to be tempted by huge price cuts and/or new technologies, some products are losers at any price. I've rounded up three I recommend avoiding.

Amazon

2. Chromebooks

Chromebooks were a sucky idea from the get-go. Take everything that's crummy about Netbooks -- weak processors, limited storage, a cut-rate operating system -- and pack it into a laptop that requires Internet access for it to be of any real use, then charge $500 for it? Yeah, can't imagine why that idea tanked.

Maybe that's why Amazon is now selling the Samsung Series 5 Chromebook for $299.99. Even at that price, you're looking at a seriously under-powered PC that's useful only for Web browsing, e-mail, and some light, Google Docs-driven office work.

In my mind, a Chromebook offers exactly one advantage over a traditional, Windows-powered laptop: fast start-up. Everything else is compromise, compromise, compromise. For all of $10 more, you can buy a full-featured Toshiba Satellite laptop (currently on sale for $309.99) that blows the Samsung out of the water at nearly every turn.

Trust me: Chromebooks will be a forgotten footnote in computing history, just like Netbooks.

ebestshop4u

3. Off-brand tablets

A tablet is a tablet is a tablet, right? Why spend $500 on an iPad or even $200 on a Kindle Fire when you can get the Pandigital Planet 7-inch Android tablet for $99? Or a MID 70009 Android tablet for $72.95?

Because they're terrible. Most of these dirt-cheap tablets have excruciatingly slow processors; you tap an icon, and nothing happens for several seconds. Scrolling a Web page can be an unresponsive exercise in frustration. The usability here pales in comparison to what you get from a more mainstream tablet.

What's more, some bargain tablets employ resistive touch screens, which require physical pressure. That's in contrast to the capacitive screens used in better tablets, which respond to the slightest brush of your fingertip. With a resistive screen, you have to push -- and that ruins the entire experience. Plus, with those slow processors, it's very difficult to tell if the tablet has registered your input, so you end up push-tapping again -- often with unwanted results. Bleh.

Another big issue: no Google Play (aka Android Market), meaning you're severely limited in the apps you can add. They might have knockoff app stores, but with none of the apps you'll want. No Angry Birds, No Kindle, no Facebook. Double-bleh.

Recently I've seen some attractively priced 7- and 10-inch models with fast processors, capacitive screens, and even Android 4.0 (Ice Cream Sandwich), but still no Google Play (or, for that matter, Amazon Appstore). Trust me: You won't be happy without at least one of them.

What are your thoughts on all this? Do you think AirPlay speakers are worth the premium? Is your Chromebook the greatest thing since microwave popcorn? Did you score an awesome off-brand tablet? All dissenting (and, ahem, supporting) opinions are welcome in the comments.