user: Janet is considering two options to retile her bathroom. The turquoise tiles cost $13/tile and the purple tiles cost $11/tile. If Janet needs to tile two walls that measure 5 feet by 8 feet and 7 feet by 8 feet, and each square foot of wall takes 4 tiles, how much will Janet save by buying the purple tiles instead of the turquoise ones? Let's think step by step and output the final answer after "####".
Answer: 768