I have bought a smaller 36 L from a brick and mortar shop for $193. But I could have got a larger size but cheaper from this ebay seller. I bought another backpack from this seller and they seem to be quite good.
It might not be the cheapest worldwide (esp if you have another ebay 15% off) but it's cheap and fast for an AU seller.
Can recommend Osprey, backpacks are solid with well thought out design features