Some background: I volunteer for a non-profit organization that holds classes over the weekends during the summer. My class, filled with 9 to 13 year olds, just finished an Egg Drop project (build a device to protect an egg as we drop it out the 3rd floor window). The group that won has a 9 year old and an 11 year old. Both are boys.
Now, I have two weeks to figure out prizes for these two kids. Any ideas? Since we're on a non-profit budget, I'd like to keep the prizes under $20 each. At the same time, I want it to be cool enough to encourage the other kids to work harder for their next project (bridge building).
Current ideas: official-size soccer/basket/football, lego set (though it would be small since legos are pricey), play-doh set, air-pump plane
I thought a 9+ year olds would like a sports ball of some sort, but my gf, who volunteers with me, thinks it's boring. She was leaning toward play-doh, which I thought was more appropriate for 5 year olds.
I need suggestions on prize ideas for 9 and 11 year olds for under $20 each.