{"explanation":"660 g = first 500 g (\\(\\$5.20\\)) + 160 g above 500 g. 160 g counts as 2 additional 100-g steps = 2 \u00d7 \\(\\$1\\) = \\(\\$2\\). Total = \\(\\$5.20\\) + \\(\\$2\\) = \\(\\$7.20\\)."}