<image> The school needs to paint the four walls and the ceiling of the conference room. The conference room is 24 meters long, 7 meters wide, and 3 meters high. Excluding the door and window areas of 22 square meters, 0.5 kilograms of paint is needed per square meter.
(1) How many kilograms of paint are needed to paint the conference room?
(2) How can the purchase be made in the most cost-effective way?