For one thing, with that much weight, you don't need to carry it on your back. Secondly, price difference is not that much when you consider the longevity of the case and the assurance that even if you banged your case, your stuff is well protected. I've got a LowePro 350 and a ThinkTank Retro 30. I can use them for a days strolling and snapping, but I don't think it offers the same protection as much as the Peli does when in long haul transport. I would still bring my Retro with me and use it in my destination.