A pair of white gold cufflinks, a fine Swiss watch, and a set of stainless cutlery will last a century. An HDTV, a laptop, and an iPod will not – which makes knowing when to break out the high-limit American Express and invest in something nice, and when to make a trip to Wal-mart and buy the cheapest box on the shelf, a tricky game.

On one hand, everyone would like to own a Dell Adamo, a Sonos music system, and a 50-inch Pioneer Kuro. But then again, most of us would love mansions and Ferraris, too. So unless you’re reading from a teak deck on your sailboat in the French Riviera, it might be wise to figure out where to spend and where to save.

While it’s a highly subjective matter (some people just to have to own a TV bigger than the neighbors), here, we take a look at every major category of consumer electronics device, and explain why some are more worthy of your discretionary funds than the rest.

HTC Hero

Cell Phones

Verdict: SPEND

We’re always amazed at how many people will hem and haw over the $50 price difference between a $100 and $150 phone, choose the cheaper one they don’t like quite as much, then turn around and sign up to pay $60 a month for the next two years for the privilege of using said phone. (That’s a $1440 commitment, by the way.)

Consider: Most cell phone owners use these devices every single day, multiple times a day, making them almost like a second appendage. And if you ask us, that’s a pretty good reason to spend some extra money, especially when most folks will be stuck with their choice for two years before getting another opportunity to upgrade for cheap.

Of course, the same advice doesn’t necessarily apply for choosing a cell phone plan. If you can get by with a $40 plan instead of a $60 plan by skipping out on unlimited data transfers, that’s $480 instantly trimmed over the life of your contract. As long as you can forgo browsing Wikipedia on the bus and chronically check the weather every six minutes, that’s a nice chunk of money waiting to be saved.

Canon Powershot SD1100IS

Digital Cameras

Verdict: SAVE

One visit to Flickr and you might be pretty much sold on a $1400 DSLR, which can do some incredible things in the hands of a seasoned veteran. But unless you’re pursuing photography as a serious hobby (and ready to study that DSLR manual like a college calculus textbook) or trying to go pro, it doesn’t make sense to spend that much on a camera when you can get 90 percent of the image quality for just a tiny fraction of the price.

From a practical standpoint, even the cheapest point-and-shoot is much smaller than a DSLR, making it much more likely you’ll have it around when that amazing photo op presents itself. And the less expensive the camera is, the more likely you are to take chances with it, like dragging it along on your next camping trip or breaking it out by the poolside to shoot a splashy game of water polo.

Keep in mind: We’ve seen some amazing shots with a $150 camera. So while the DSLR has its place as the weapon of choice for serious photographers who demand the absolute best, most consumers are better off saving their pennies for elsewhere.

Altec Lansing Model 19

Home Audio Equipment, Speakers and Receivers

Verdict: SPEND

Good stereo equipment stands the test of time. Try hitting eBay or Craigslist for a pair of vintage Altec Lansing Model 19 speakers for proof that a quality speaker in 1977 is still a quality speaker today (you can expect to part with about $1500 for a pair).

That’s not to suggest that modern speakers won’t lose value over time, but the high-end home audio world works on a glacial time scale compared to the rest of the over-caffeinated consumer electronics universe. Therefore while today’s TVs might look as dated as tube sets in 10 years, a nice pair of speakers will still play Lady Gaga with aplomb. (Although something tells us her music will sound a lot more embarrassing in 10 years than the speakers will.) And if you decide to sell them, they might actually fetch a nice resale price, rather than getting you laughed out of the flea market.

Of course, it’s important to make sure that you can actually appreciate high-end audio before dropping a significant chunk of change into it, and don’t forget that mass-market audio equipment will lose its value the same way everything else does. Nobody pays top dollar for a boom box in 2009.

Falcon Northwest Mach V

Desktop or Laptop Computer

Verdict: Desktop – SAVE, Laptop – SPEND

Until PCs begin performing some amazing new function that only the best-equipped among them will actually pull off, you’re far better off going for a budget box than shelling out for that $4000 Falcon Northwest system. These days, an $800 desktop model will run Windows 7, surf the Web, teleconference, edit video, play back 1080p HD video, and even play modest computer games without flinching. Put simply, computers have gotten so powerful that the list of the reasons to spend over $1,000 on a computer has pretty much been whittled down to gaming performance and style.

The ease of upgrading a computer also points to taking the cheap route. Should you decide to, say, buy a PC with a 320GB hard drive today and fill it up with movies in the next six months, don’t forget. You can always go out a buy a bigger hard drive when you need it, for cheaper than it would have been when you bought the system. Suddenly realize that you’re interested in games as well? Hey -  just drop $100 on a graphics card for an instant performance boost. Likewise, should you want to talk to friends on the other side of the country, a $40 webcam will do the trick.

Mind you, since laptops lack the same range of expandability as desktops, we’re inclined to edge our advice in that category a little closer to “spend.” You won’t be able to upgrade every piece and part as you go, and since they’ll take a beating, build quality and weight play a far larger role.