Recently when I was packing for my two week trip to Israel I forgot to weigh my luggage before I got to the airport. My luggage weight was 7 pounds over and it was going to end up costing me about $100 by the end of the trip. The $100 did not even include the weight of my souvenirs!
Luckily, my co-workers who were traveling with me knew that you can purchase a small duffel bag from the airline and it only cost me $30. The bag was a decent sized bag and not only saved me money but allowed me to go shopping while I was there and not have to worry about it.