Amazon sells a samsonite duffel that I bought before coming home on the train across country. Cheap and fit 3 panniers worth, handlebar bag and tent inside (I used one pannier as a carry on). I have a student amazon prime account, so I could order it ahead knowing that it'd be at my destination in 2 days.
http://www.amazon.com/Samsonite-Tote-Duffle-Luggage-Black/dp/B003KR1K40
Never tried the Amazon brand but the samsonite duffel has been great for us...no holes and it holds a massive amount of stuff. Great for household moves as it swallows up clothes and shoes like you wouldn't believe. We have four of them and use them yearly for transatlantic hauling.
https://www.amazon.com/Samsonite-Tote-Duffle-Luggage-Black/dp/B003KR1K40