Add a utility to list all cost combinations.

combination.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+
+import itertools
+import sys
+
+class Main():
+    def main(self):
+        costs = list(map(lambda x: int(x), sys.argv[1:]))
+
+        for cnt in range(1, len(costs) + 1):
+            for item in itertools.combinations(costs, cnt):
+                cost = sum(item)
+                print('{}: {}'.format(cost, list(item)))
+
+if __name__ == '__main__':
+    Main().main()