1 files changed, 4 insertions, 2 deletions
diff --git a/Cost.hs b/Cost.hs
index dc2438e..a18a088 100644
--- a/Cost.hs
+++ b/Cost.hs
@@ -92,6 +92,7 @@ estimateAttackCost dc opcost = centsToDollars $ costcents
 newtype Cents = Cents Integer
 	deriving (Num, Integral, Enum, Real, Ord, Eq, Show)
 
+-- | USD
 newtype Dollars = Dollars Integer
 	deriving (Num, Integral, Enum, Real, Ord, Eq)
 
@@ -103,12 +104,13 @@ instance Show Dollars where
 		, (1000, "thousand")
 		]
 	  where
-		go [] = "$" ++ show n
+		go [] = fmt (show n)
 		go ((d, u):us)
 			| n >= d = 
 				let n' = n `div` d
-				in "$" ++ show n' ++ " " ++ u
+				in fmt (show n' ++ " " ++ u)
 			| otherwise = go us
+		fmt d = "$" ++ d ++ " (USD)"
 
 centsToDollars :: Cents -> Dollars
 centsToDollars (Cents c) = Dollars (c `div` 100)