This guide will help you to navigate through the most common problems of shopping for (and buying) a used cell phone on eBay.  The most common reason anyone shops for a used phone is to obtain a replacement for one that was lost or broken. Figuring out what to buy becomes clearer if you know what you need. 

The world of cell phones is a bit bewildering to a novice shopper. You can simplify it all by asking yourself three questions:  Are you under contract right now with a carrier? Where are you planning to use the phone? What do you want it to do? The answers to these simple questions will help you move into the eBay buying arena as a pretty aware shopper.

First, why does the carrier matter?    Most people start out their life as a cell phone user by going into a carrier's store, where they buy a shiny new phone in a box.  They are a bit giddy with the "new phone smell", enjoy their new toy, and perhaps several months later, become more aware that they have entered into a lengthy contract, usually for one or two years, with the carrier. 

If their phone becomes lost or broken, a new replacement from the carrier becomes shockingly expensive, usually several hundred dollars.  This is because that first phone is heavily subsidized by the carrier - most carriers will practically give a customer the first phone in order to get them under a lengthy contract. The obligation of the contract means that the customer must continue to pay for use of a minimum number of minutes for its duration. Thus, if anything happens to this first phone, a good used phone is in order. The cost will be a fraction of the new phone, and most often with all the same functionality.

If you are now in a contract with a carrier, and if you want to continue with that carrier, your best bet is to buy a phone that will work on that carrier's network. The easiest way to be sure of this is to buy a phone that has previously worked on that network. In the most practical (and non-technical) terms, this means that if you are with Sprint, you should look for a phone that was issued by Sprint and has worked on the Sprint network. Each carrier's phone is loaded with very specific software, which helps it to find that carrier's network. So if you have a contract with Verizon, buy a Verizon phone. If you are with AT&T, get a phone that says AT&T right on the phone. And if you are with Cingular, get one that says Cingular on the housing.

Forget about the big company mergers. A phone that was loaded with Cingular software will not suddenly know how to work with AT&T.  If you are a technical novice, this simple policy of matching the previous carrier to your current one will save you much misery resulting from technical incompatiblity, and you won't even have to learn the technical jargon.

Where will it be used, and why does that matter? Cell phones operate through different technologies. The two most common, GSM and CDMA,  are used by the major carriers throughout the United States. If you know where you are going to use the phone, you can locate the carrier with the strongest network in that area.  Then you will be less likely to have dropped calls or have to live with a weak signal.. If you are in a mountainous or remote area, talk to others and find out what the best carrier is for that area. Reception and price may depend on the location of the towers and who owns them. If you need a nationwide network, sign up with a carrier that promises one.

What do you want the handset to do?    If you just want to use the phone for basic or emergency use, you need a strong signal and a good battery, which you must keep charged.  You may want or need more sophisticated features. Do you want a camera embedded in the phone, with a picture phonebook? Variable and polyphonic ringtones are nice. Do you use text messaging or browse the Internet? If so, you may want a higher end handset with these features. Study the listings carefully, as you will learn a lot by searching the categories to find out what is available and what the costs are.  Does style matter to you? Most listings have pictures of the phone, and the technical specs in the listing will tell you more details, such as battery type and standby time.   I'd advise that you shop by carrier first, then narrow down the search.

With a used phone, you can't be sure about the battery strength, so once you are enjoying your dream handset, you may want to shop for an additional battery and a car charger. You probably should look for a headset if you use the phone in a car.   EBay is a great secondary market for all your phone needs!