My limited experience was with the free version of Hammersnipe (there is a pay version, too). For times when you get outbid based totally on timing (ie. entering the bid the last 1-3 seconds of the auction), this might be a solution. It bids automatically for you at the end of the auction, based on your criteria.
But, for times when you are outbid based on your max. bid price, there is no program that will help.