dfn_deux I am not sure if I understand what's the problem. Suppose, there is a car worth 3000$ (according to some average price on the market), someone wants to sell that car and initiates auction setting starting price to 1$. Not many people are interested and the highest bid is 1000$. Unfortunately, poor seller forgot to specify minimal bid (e.g aforementioned 3000$) and instead of withdrawing the car from the auction needs to sell it for 1/3 of its market price.

As far as negative bids, there are such auctions. Instead of buying goods people buy services. The best example is rentacoder.com, but I've heard of an internet auctioning web page where one can "sell" e.g. bathtub replacement. Companies and individual plumbers bid offering smaller costs. This can be considered as negative bids.

dfn_deux I thought that your initial post is a joke because according to some theories in economy goods are worth what other people are willing to pay for them. Therefore, any winning bid on an auction is what should be considered as a market price. You didn't specify that this was your intention.