Flight pricing errors are a godsend for wanderlusters with big dreams, but small wallets. It's like opening that crinkly take-out bag, and realizing you got an extra set of fries with your order... Only way better. There are a number of websites that claim to offer “mistake fares” - seats available for prices well below the typical cost of a flight. Some sites are better than others, but the only surefire way to get access to these “mistakes” is if you have some insider knowledge. Read…