For DS, we hot glued 100 googly eyes (picked up at the $1 store so maybe $5 max) to an older t-shirt. The shirt got put into his "remember when" box with various art projects and papers in the attic.
For DD, she brought in 100 temporary tattoos to pass out to her friends and 100 strawberries for snack that day to share with the class.
Neither one had to wear the 100 count item ~ 1 chose to while the other did not. There were several other inexpensive items we could have chosen using the $1 store craft area - silk flowers, pom poms, stickers, etc.