I completely understand that it's annoying when it happens but my view is that it's the seller's fault rather than the buyer's. A lot of sellers start their auctions off at a price so low that it looks too good to be true. In a lot of cases it usually is. Some sellers tend to do this in the hope of attracting a rush of bids for the item from several potential buyers all keen to win the item for a bargain price, the end result being that so many people bid that the winning bidder ends up having to pay quite a high price for the item. Unfortunately for the seller this tactic does not always go according to plan, the end result being that when it doesn't the item does not attract enough bids for the final selling price to reach the minimum amount that the seller was prepared to sell the item for. In instances such as this the seller will often renege on the deal; however, if the seller had started the auction off at a price that he/she would have been happy to sell the item for had the item only attracted one bid then this situation would not have occurred and both buyer and seller would have been happy with the final selling price.
At the end of the day all you can really do is leave the seller appropriate feedback as to how you feel the transaction went, then move on and see if you can find a similar or identical item being sold by another seller and hope that you won't get messed around by the next seller.
