$85 (rrp over $250) OGIO 160litre heavy duty luggage roller bag.
Designed for motorcross use but I've only ever used for clothes- used only a couple of times so in great condition.
This bag is massive! 36"w x 17"l x 16"h
More specs here (Bag no longer has dividers or mud flap): http://www.dogfunk.com/ogio-9800-rolling-gear-bag-9800cu-in