we have been through so many backpacks/lunchbags. Sometimes they were ripped and could only be patched so much after a couple of years. One year we had to switch to a wheelie bag because of the weight of the books going back and forth. Then we had an issue because the wheelie bag wouldn't fit in lockers that the kids had to use the next year.
If a bag that isn't being currently used is still in good enough condition to be used, it gets repurposed for sports equipment, or overnight bag or day trip pack. We aren't filling the landfill with bags that can still be used.
My younger son was very unhappy to have to change schools this past year and we got get him a new minecraft backpack that he was wild about to help that transition.
Usually, the llbean or landsend bags go on clearance in the spring, and we have bought bags then before.
At various points, each of our kids have gone to schools where the zuca bags are THE bag that most of the kids have. After dealing with those prices, buying them a $20 bag is NBD. We were lucky to get a zuca bag used for $50. This is what the zuca bags looks like:
They run around $150-200 for the frame and the insert.