An enterprise plans to consume 200 kilograms of A material in the year, and the cost of each order is 800 yuan. The unit price of the material is 80 yuan, and the unit storage cost is 800 yuan.

(1) Calculate the economic purchase volume of the material;

(2) If the supplier offers a trade discount, and the unit price of the material is 28 yuan when the purchase quantity exceeds B600 kg, what is the more economical one time purchase?