I like the idea of trading unloved supplies.
There are also tons of things you have around the house that work wonderfully: paper clips, staples, all other kinds of office supplies like tags, labels, etc...acrylic paints, sponges or other items to make a pattern with, old cards, buttons, ribbons, fabric, soda can tabs. I've seen people use their son's toy cars and run the tires through ink and then make a pattern on the paper.
I also like to make as much as I can with paper and have pretty much done everything I can: sew, crumple, ink, tear, paint, bleach, make flowers, borders, etc... I now buy a lot of tools to do more things to it.