One should always use local pricing when available. Typically a bag of play sand is 1/2 a cubic foot, so twice the price will give you the local unit price for a cubic foot of play sand. However, for convenience, vCalc performs a periodic survey of commodities such as play sand. The most recent play sand survey was as follows:
Good play sand is different than sands used in other purposes in at least two ways. First, it is washed to remove chemicals and particulates that could be a health hazard. Second, it is sifted to a consistency good for children's play. Play sand typically comes in bags of about 50lbs that hold a half of a cubic foot of sand.
... common brands of play sand ....