While it's not a 100% analogy, it's 99.99% - Good Delivery gold bar are virtually never converted to smaller units. Indeed, it's rare that they are ever even moved from their vault (though that does happen on occasion).
The point I was trying to make is not that Gold Bars are impossible to make smaller, but that their very high price "per unit" doesn't result in any lower-prices per ounce than if they were broken down into smaller units. I.E. There is no pressure to reduce the size of Good Delivery Gold Bar's - the market realizes that just because they are expensive per unit, it doesn't reduce their price per ounce.
The point I was trying to make is not that Gold Bars are impossible to make smaller, but that their very high price "per unit" doesn't result in any lower-prices per ounce than if they were broken down into smaller units. I.E. There is no pressure to reduce the size of Good Delivery Gold Bar's - the market realizes that just because they are expensive per unit, it doesn't reduce their price per ounce.