Electronics are expensive and expendable, making them a likely candidate for resale if someone's looking for quick cash. But most should be avoided unless buying from a reputable dealer who's willing to include a warranty that covers the risks. Here are some prime candidates to give you buyer's remorse.
Projection TV: Large projection sets use expensive bulbs with limited life spans, and it's impossible to know how close they are to burning out. Sets older than a few years, in particular, used bulbs that burned out rather quickly. A new bulb can cost $300 or $400. Some projection sets also have moving "color wheels" that are subject to wear that might lead to failure.
Standard DVD player: These have too many moving parts that might be ready to fail, and new standard DVD players are too inexpensive to justify the risk of buying used. The internal lasers that read the disks also wear out and are too costly to make replacing them worthwhile.
HD DVD player: Toshiba's format just lost the battle to Sony's Blu-ray, so movies will be hard to find in high definition. These players do also work as a good, upconverting player for standard DVD disks, but smaller and more attractive models that do the same thing can be found new for $50 and less.
MP3 player with hard drive: Avoid used iPods and other players with hard drives for storage—unless the price is good enough to cover the cost of replacing the drive.
Computer: It's rare to find a used desktop or notebook PC with a price that justifies the risk. Only consider desktops less than a year old, and laptops less than three months old, that are offered at a substantial discount. A desktop that appears to be in good working condition still has too many moving parts, including hard drives and fans, that are subject to wear and tear. Laptops have the same moving parts and get subjected to bangs and bruises in transport.
Digital camera and camcorder: There are too many moving and precision parts in hand-held devices that are commonly dropped. Stick with reputable dealers of used equipment who will also offer a warranty of 90 days or more.