If you need a decent lightweight backpack that is well-built and affordable, this one is only $23 plus like $5-6 shipping/handling ($20 if you buy 3 and shipping does not go up with more units.). It is an off label model of a name-brand product. I bought a second one to add to my preps in addition to our heavy duty bug out backpacks. I am using one for a radio and laptop pack.
https://thatdailydeal.com/fasttrack/fast_track.php?id=56612&chksrc=txtConsider subscribing to this website as they often have useful items at a discount. They do repeat these products on sale sometimes. So if you are working on a Lenten goal not to shop or having a "no buy" month (like I am doing for February), they will likely come back around again.
Personal note: My husband has bought gas for my car and milk for us, but that is all I allowed. If SHTF happened, then we would have used powdered milk and not driven as much as possible.