Alyssa is making 30 centerpieces for tables at the junior prom. She will place 8-inch tall cylindrical candles into vases shaped like square prisms of the same height. Then she will fill the space between the candles and the vases halfway with sand. Sand is sold in 115-in 3bags at $15.75 per bag. How much will Alyssa spend on sand to create all 30 centerpieces? Show your work, or explain how you found your answer. You cannot buy partial bags of sand!