I did the same thing awhile ago about one of her purchases. Her response was spot on as your wife, "a lot less than the expensive toys you buy".Me too. My wife is the super saver. A while back she bought some puffer thing that blows germ killer into the air - or something. Out of curiosity I asked what it cost? Her answer - "a lot less than one of your tires". LOL Lesson learned - never question what the wife spends.
She saves and watches the budget. So when she buys her little trinkets I keep my mouth shut.