I will be going on a trip all over the country this summer and want to get a decent camera backpack for my stuff. I want to carry my camera, the two lenses I have for it, some spare camera gear, as well as room for extra, non camera related items. I would really prefer one with comfortable straps and waterproofing as well. Here's the kicker... My budget is no more than $50. I would really appreciate help in this area. Thanks in advance!