I am not sure if you have a Riot craft store near you. I picked up 5 craft packs for $5 last week. Whenever my tots need a little direction I get one out and we have some quiet time. The kits have everything in them including craft glue.

**** Smith have electronics kits that are pretty cool. They are mostly under $20 and they are suitable for school aged children.

Lego competitions - who can build the tallest free-standing tower in 10mins.