I have a secret about sand. Every other spring we refresh our sandbox with some new sand. I have found the most cost effective way is to find a sand a gravel company locally and fill up the back of my van with sand. The kids and I did just that the other day. With 10 – 5 gallon buckets and a shovel we headed to the sand and gravel pit. I backed my van up to the bay with the sand and started shoveling, while the kids watched the huge dump trucks get filled with sand and gravel. In the end 10 buckets = $10.00.