The Worst Buys on eBay

Generally, you can expect to save 30% to 50% off the retail price of a given item, says Julia Wilkinson, author of "The eBay Price Guide," which assesses average prices for items in every category.

But there are also plenty of potential rip-offs. Some, like the T.M.X. Elmo dolls listed for $5,000 or more, we hope no one would be foolish enough to bid on. Others are a bit tougher to spot.

We've collected four pitfalls that lead to rotten deals:

1. Beware Emotional Bidding Wars
There are plenty of die-hard Cardinals or Tigers fans who wanted Game 5 World Series tickets — especially two box seats within spitting distance of first base. On game day, tickets sold for $2,750. Priceless? Maybe. But seats in the same row and section could be had for a flat fee of $1,360 at TicketsNow.

Solution: "There's an adrenaline rush when you bid, and it's easy to get carried away," says Marsha Collier, author of "Santa Shops on eBay." "You don't go into a store and act silly like that. You look at the tag and decide if it's too expensive." Determine the maximum you're willing to pay, and then make a bid for that amount. (Don't worry, novices: The site will start you off with the lowest bid possible and then increase it incrementally should others bid against you.) For best success, wait until the last minute to make your move, says Wilkinson. Bidding early draws the attention of other would-be buyers. If you're outbid, try again with another auction.

2. Overpriced Shipping
If you want a sleek iPod 2GB Nano, there are plenty of options to buy one on the cheap on eBay. They're currently going for an average of $132.33, according to Honesty.com, a site that tracks eBay prices. That amounts to a discount of 11%, before figuring in shipping or sales tax, off the $149 you'd pay buying directly from Apple.

Want your iPod fast? Plenty of sellers can do that, too. We spotted a listing offering overnight UPS shipping for $46.98. Problem is, that sleek Nano weighs less than two ounces; packaged, still less than one pound — which puts the UPS Next-Day Air rates at only $29.40. A quick glance at the seller's feedback also turned up three negatives, all for slower shipping than the buyers paid for.

Solution: Check the listing for shipping prices or estimates before you bid. And don't forget sales tax — some sellers do charge it.

3. Hot-Trend Items
This holiday season, parents would give anything to see red — the fire-engine-red fur of T.M.X. Elmo, that is. This hot holiday toy goes for $39.99 in stores (assuming it's ever in stock). On eBay, the average bid for the toy is currently $60.90, though some are fetching as much as $122, according to Honesty.com.

Solution: Claims of "sold out" are often exaggerated, says Collier. Before you bid on a must-have item, do some digging to see if you can get the item at retail price through other means. Take Gap's popular (Product) Red line, which gives a portion of its profits to the Global Fund to Fight AIDS, Tuberculosis and Malaria. The wares are advertised on eBay as "sold out in stores and online," but it's still fairly easy to find the products in stores. (See our story for more tips on finding the elusive T.M.X. Elmo.)

No luck? Determine how much more you're willing to pay for the convenience. "How much is your time worth?" asks Collier. "How many stores would you have to go to otherwise?" Then stick with your maximum bid.

4. Fakes
You've spotted it — the Christian Dior Gaucho, a handbag fashionistas are clawing each other over, for only $58 on eBay! Given that the bag normally retails for at least $1,660, it seems almost too good to be true...and it probably is.

Solution: Be wary of "authentic" items that are going for much less than the original retail price. "You're going to pay a lot closer to retail for designer brands," says Wilkinson. In part, that's because these luxury items are desirable, and so are heavily bid on. It's also because resale values are high, unlike that worn and washed Banana Republic sweater. (For tips to spot fakes, see our column Fab or Faux?)