Gold and Silver are only really worth what people expect them to be worth. See Diamonds for an example of marketing making it a commodity. Gold and Silver are *precious* but even a hundred extra accessories worth of Gold and Silver shouldn't be an impact on the economy.
Also, it isn't like he has given away buckets of the stuff, he literally made them for his Mom, Sister, and a couple of Nurses he also wanted to help because they probably are as fatigued as his mom. These are people he knows, and the guy has never been shown so far to be selfish. In fact he has literally been the opposite and is otherwise very thoughtful of people he knows. Hence the whole send enough Parfaits to not just the group of girls, but the brother and the King as well. (The fact that they didn't receive it isn't his fault)