eBay is a very useful source for new and used shortwave radios. It can enable you to purchase a radio that's not marketed in your home country, or to save money by purchasing a used radio. I've been watching shortwave radio offerings on eBay, and I've also made three purchases. Here are tips for anyone interested in purchasing a shortwave radio through eBay. Some of these tips may be obvious to experienced eBay users.
For the most part, I'll assume you already know what features you want. If you're new to the hobby, be sure to read Selecting a Shortwave Radio at dxing.com.
* Avoid auctions or "buy it now" listings with a very low item price and a high shipping price. I recently saw auctions for Tecsun PL-550 radios for $0.99 with a shipping cost of $84.00. Seven-to-ten day airmail shipping of a radio from China to North America might actually cost up to $20. The seller put almost the entire price within the shipping fee as a way to avoid paying eBay fees. Auctions priced this way should be reported to eBay for attempted fee avoidance. It is not just dishonest; it can pose a big problem if you try to get a refund. The seller can claim that the refund does not include the shipping cost.
* Radios shipped from China may have Chinese labeling, Chinese manuals, and 220v power supplies. If you are considering purchasing a Chinese radio, find out if a translated manual is available. If not, find out if the radio is sold in North America under a different brand/model, in which case you might find a downloadable manual for that radio. For example, the Tecsun PL-200 is the same as the Eton E100. You will also need a step-up power transformer if you wish to power the radio from a 110v wall outlet.
* If you care about AM broadcast (medium wave) reception, determine the radio's step size (if digitally tuned) and frequency range. In Europe and Asia, AM stations are 9 khz apart whereas in North America they are 10 khz apart. If you're considering a digitally-tuned radio that has up/down buttons for frequency scanning, determine if it comes with the correct step size or allows you to toggle it between 9 khz and 10 khz. North American AM stations can be as high as 1710 khz whereas some radios manufactured today may only go as high as 1620 khz.
* Sometimes a manufacturer releases an update of a particular radio model to correct problems. Try to determine if you are getting a problematic first-run radio or a revised, corrected one. I don't think this can be determined from a serial number, but you might be able to determine the manufacturing date. Whenever I want to learn about a particular radio, I start with a google search like "ka1103 review" to learn about the Kaito KA1103, for example. Radiointel.com has detailed reviews of many current shortwave radios, and some reviews mention known manufacturing issues.
* When purchasing a radio that has been taken out of the original box, determine if the offered item includes all of the accessories that you require. Find out if you will receive the manual and power adapter. Check the manufacturer's homepage to determine what is included in a new package.
* I saw at least one auction where the title and description described a much newer radio than was depicted in the picture. If you're not familiar with the radio in the auction, visit the manufacturer's site or do an images.google.com search to determine if the description matches the picture. If an auction advertises a Grundig radio designed by Porsche, be wary if the picture shows an old, plastic radio with an ugly interface!
* Edit: Ulis aka K3LU from RadioIntel.com adds this tip regarding warranties: "While buying direct from China frequently offers a savings, keep in mind that if the radio arrives defective or has a defective issue within a normal warranty period (say 90 days or 1 year), the value of the radio may not be worth the postage to send the radio back to China for replacement or repair. In other words, there is a risk factor involved. All US distributors on new radios offer a warranty."