Help Me With a graduation gift ?

okay so i'm the one who needs to be checking everything to see if its right and prom things , flowers , lights .everything !!! but the money we have ...we have like 421 dollars that we don't need so i thought with that money we could buy a cheap like 9-10 dollars gift for everyone we are like 32 only. So thats what i thought umm..but i don't know what ??? any ideas that is like 9 or 10 dollars. and somethings for girls and boys.... !! remember 9-10 dollars , some ideas for girls and other for boys. somethings that we can remember .for our prom....