Since my church has a packing party each November, I am always on the lookout for items that I can purchase in bulk. I first saw building bricks featured on Clip with Purpose earlier this year. Building bricks are simply Lego type bricks.
1000 piece packs from Amazon for $39.95. Amazon also offers a 500 piece pack for $24.95. I put between 30 and 40 pieces in each of our 5-9 and 10-14 boy boxes. These would also be great in girl boxes too. My testers are the children in my Sunday night Bible class. Their ages range from 5-13. Everyone enjoyed trying out the building bricks, and they were a definite hit.