Back out of an auction before it's too late.
There are a lot of reasons why you might want to back out of an auction after bidding. Obviously, if you make a mistake and bid the wrong amount or bid on the wrong auction, you'll want to retract that bid before the auction ends and you're obligated to pay.
But there are other reasonable circumstances under which you may change your mind about an auction. Sellers can make changes to the description or photos, even after the item has received bids (see [Hack #50]), and such changes may affect your desire for an item or your ability to pay for it. Or, if you lose your job and find your daughter needs braces, your desperate need for that 42" plasma TV may become slightly less desperate.
eBay takes bidding very seriously, to the point of imposing restrictions as to when and under what circumstances you can retract a bid. This is understandable, considering the scams a small minority of eBay users have propagated; look up "buying offenses" in eBay's Help for an exhaustive list (and lots of ideas, too).
The easiest way to retract a bid is to use the "Retract my bid" form. Simply enter the auction number, choose one of the prewritten excuses from the list, and click Retract Bid. (It doesn't really matter which reason you choose; the end result will be the same.) All your bids on the auction will be canceled, and the auction's current price will be adjusted accordingly.
The problem is that any bid retractions will be shown on your feedback page for six months, and while it doesn't actually affect your feedback rating, excessive bid retractions may make you appear less trustworthy and certainly less serious. Furthermore, a pattern of bid retractions may arouse the suspicions of eBay's investigations department; at the extreme, your account may be suspended if eBay suspects abuse of their system.
This is also where eBay's restrictions come into play: during the last 12 hours of an auction, you are not allowed to retract any bid placed before the final 12 hours. Furthermore, if you bid in those last 12 hours, you can only retract your bid within one hour of placing it. Note that because of this restriction, sellers are not allowed to make certain changes to their auction within the last 12 hours.
 The idea is to curb two different kinds of bidding abuse: shill bidding (where a friend of the seller bids to raise the price) and bid shielding (where a friend of the high bidder bids high and then retracts so the auction ends with an artificially low price).
If you find that you need to retract a bid but either don't want to or, due to eBay's restrictions, are unable to, you can still contact the seller and ask to have your bid canceled. A seller can cancel any bid on his or her auction at any time, and for any reason.
Keep in mind that you're asking a favor of the seller by requesting to have your bid canceled, so be especially polite and apologetic. Here are a few examples of good excuses:
"Would you mind canceling my bid? I just read your auction more carefully and discovered that I'll be unable to pay. I'm sorry for the inconvenience." The last thing the seller wants is a deadbeat bidder, so make him feel it's in his best interest to cancel your bid. But try not to give the impression that you simply didn't read the description before you bid.
"Could you possibly cancel my bid on auction #3125058177? I made a mistake in my bid, but since there are fewer than 12 hours left in the auction, eBay won't let me retract." eBay's bid retraction rules can be a little confusing, so don't be afraid to educate the seller on eBay policies.
The decision of whether to grant your request is completely up to the seller, and there are valid reasons why he may not agree. For example, if there's more than one bidder, canceling your bid may lower the current price. Or the seller may be desperate to unload the item, and if you're the only bidder, you're his ticket to freedom.
The following excuses will probably just anger the seller, and should be avoided:
"I just bought another one of these from another seller on eBay, and I no longer need yours." You should never bid on multiple auctions when you only intend to pay for one, and sellers know this. If you're currently the high bidder, the seller may let your bid stand just to teach you a lesson. (See [Hack #23] for a safe way to bid on multiple auctions.)
"I noticed another auction with a lower price, so I'd rather bid on that one." This is a slap in the face, and a clear indication to the seller that you're wasting his time. Again, he may leave your bid intact out of spite alone.
Like much of using eBay, getting out of sticky situations requires diplomacy, careful wording, and an understanding that you won't always get your way.
eBay is a community built on trust, as well as an understanding by buyers and sellers that successfully completed auctions are legally binding contracts. But it's also naïve to expect that all sellers are trustworthy and all transactions can go smoothly. Sometimes, you need to back out.
The easiest ? and worst ? way to back out of an auction is to simply not pay. Ignore all a seller's emails and the eventual payment reminders and warnings from eBay. Do this once, and you'll get a nasty, negative feedback comment from the seller. Do this three times, and you'll be suspended from eBay indefinitely.
Only the seller can release you of your obligation to pay for an auction you've won, so it's typically a matter of delicate diplomacy to try to convince a seller to consider the auction void and not retaliate with negative feedback or non-paying bidder filings. See the previous section for some examples of approaches that work and some that don't.
 See [Hack #71] for tools available to sellers for dealing with deadbeat bidders.
If you decide not to complete a transaction because you suspect fraud of some sort (see [Hack #28]), the first thing you should do is contact the seller and express your concerns. For fear of eBay cracking down and possible legal consequences, the seller will probably just let it drop and not retaliate with negative feedback. At this point, you can proceed to contact eBay and ask them to investigate the seller. If the seller is suspended or the auction voided, the obligation will disappear, as will the seller's ability to leave feedback for you.
If, on the other hand, there is really nothing wrong with the seller or the auction, you should do everything you can to complete the transaction. If it turns out that you simply no longer need or want the item, you can always resell it on eBay, possibly for more than you paid!