The real bargain opportunity that occurs when items are sold at no reserve, which means the high bid gets the item, even if the high bid is below market value for an item.
Sometimes auctions will require a minimum opening bid, which puts a minimum amount on the item for it to sell. This is not as good as if the opening bid were a dollar, but it is not as bad as having a reserve either, because the minimum bid is disclosed up front and you can decide whether or not to participate.
A reserve on the other hand, is typically not disclosed, and bidders bid blindly against the reserve amount. If the highest bid fails to surpass the reserve, then auctioneer is not compelled to sell the item for the high bid price. Sometimes they will anyway, just to move the item, but you have no way to know this in advance.
