It's the main thing on your mind when you walk into an electronics store: Don't get ripped off. Whether you're shopping for a digital camera, computer, or HDTV, you want to know what's a fair price, and what's a swindle. We decided to investigate the matter to find the perfect price points for common gadgets and gear in today's market. Our goal: to take the Top Five tech products people seek and find each one's dollar-value "sweet spot" — pay more, and you were either ripped off or got features you don't need; pay less, and you've either found a bargain or compromised on your product's essentials. To come up with the sweet spot for each category, we checked out the latest models and street prices at several popular online retailers including Amazon, J&R, Newegg.com, Tiger Direct, and Best Buy, then compiled the data to determine where the best deals were. So how much should you really be paying for that plasma TV, digital camera, or super cell phone? Find out after the jump.

For most people, 6 megapixels are plenty unless you plan on blowing up your pictures beyond the size of a magazine page, so the key features to look at in a camera are lens quality, viewscreen size, flash performance, and overall size. While some 6-megapixel cameras can be found for well under $200, these budget models usually lack some fairly basic features like a viewfinder (Pentax Optio M10 and Olympus S600), or a macro lens mode for taking those ultra close-ups of things you plan to sell on eBay (Sony DSC-S600). Step up by about $50 and you'll find all of these important features, along with quick response, and a nice compact form factor. Spend even more and the camera becomes either a James Bond like tiny model like the Sony DSC-W30, or a much bigger SLR — generally a lot more camera than most people need. Sweet spot: $239.50

While smaller flat-panel TVs use the same LCD technology as a flat-panel computer monitor, those in the popular 42- and 50-inch sizes are almost invariably plasma designs. While you can get a 42-inch plasma for less than $1,500, these cheapo models with names like Wal-Mart's own Ilo brand, often have resolution that's limited to 852 x 480 pixels. That's fine for standard-definition sources like DVD movies and regular television, but it's certainly not HDTV. True high-def models usually boast 1,024 x 768-pixel resolution, which lets you to display a progressive-scan 720p image without scaling. To be sure that your purchase will take full advantage of upcoming technologies like HD DVD and Blu-ray disc, it's important to have at least one digital video input — either HDMI or DVI. If you plan on getting all your high-def programming from a cable or satellite box, you can save a few bucks on a stripped-down commercial model like Panasonic's TH-42PHD8UK, where you get great basic performance, but no built-in tuner or speakers. Otherwise a more fully featured TV like the TH-42PX60U is a better choice. Sweet spot: $2,398.24

The concept of using a separate subwoofer to handle the deep bass in a surround sound system has revolutionized home theater, allowing home theaters with small satellite speakers without giving up rich, full-range sound. The problem is that this has also made it possible to produce truly cheap and nasty-sounding rigs that will only make you want to turn it off. I would generally take a pass on the bargain-basement systems that you can probably pick up at your local pharmacy, since they usually use satellite speakers that have no separate tweeters for high frequencies. Many of these, from brands like Norcent or Coby, are no more than hijacked multimedia rigs designed for desktop use with a computer. Real speaker packages tend to come from real speaker companies (surprise!), starting with affordable models like the Athena Technologies WS-15, Fluance AV-HTB, Klipsch Quintet III, and Paradigm Cinema 70. Sure, spending above the sweet spot will get you bigger sound, more slammin' dynamics, and even more clarity, but for most folks a little more than $500 will do the trick. Sweet spot: $512.98

It's no secret that running an intensive game like F.E.A.R. or Oblivion can tax the performance capabilities of even the fastest processors and graphics cards, so to push the envelope further some serious gaming PCs employ dual-graphics cards, overclocked processors, and elaborate cooling setups to avoid a potential meltdown. While a souped-up Falcon Northwest Mach V would run any game at maximum settings without batting an eye, it'll do so for about $7,000. Most of us will find that the same games will still run just fine on a more affordable but carefully tailored system. Processor speed is a big concern when it comes to gaming, but don't overlook the importance of the graphics card, which can make just as much of a difference. Gaming-PC specialist Alienware has models all along the price scale, but the lower end models such as the Aurora 3500 are so underpowered that they won't run today's current games all that well, let alone tomorrow's. It's important to keep in mind that with gaming PCs the more you spend is directly related to how long it will be able to run the latest software. To continue the Alienware example, the Aurora 5500 will be able to adequately handle most of today's games for a touch under $1,500, but for about $300 more the Aurora 7500 doubles your graphics card processing power, RAM, and hard-disk space, making it a far better deal. Sweet spot: $1,789.77

Those of us who want all of the latest tech gadgets tend to grow weary of carrying around half a dozen different devices, but it seems like the cellphone is fast becoming the platform into which everything else is being incorporated. While the most basic models that typically come free of charge with a two-year contract are fine if all you need is a phone, additional features like an MP3 player, FM tuner, picture taking, video capture, and Bluetooth wireless support usually involve stepping up to a premium model. At the top end of the scale, there are several PDAs like the Palm Treo 650, RIM BlackBerry, and Nokia 9500 that also happen to function as phones, but most of these are pretty bulky, and not something non-business folk would want to carry everywhere. For most of us, a full-function phone with Bluetooth, MP3, and video capability such as the Sony Ericsson W600i will do what we want without ruining the line of our suit jackets. For business users who really feel the need for PDA-type functions but who can live without a camera, the Samsung SCH-i730 manages to pack in a lot of features without packing on too much bulk. Pricing phones is particularly tough as much of your choice will depend on the carrier you use and whether you are eligible for a periodic phone upgrade discount, so our guideline is based on a street price without any carrier discount. Sweet spot: $336.84 (before provider discount)

— Michael Trei