You may not know beforehand that the smallest unit is $0.01. What if it becomes $0.001 or $0.0001 later? You'll have to migrate your data to use the new smalles

You may not know beforehand that the smallest unit is $0.01. What if it becomes $0.001 or $0.0001 later? You'll have to migrate your data to use the new smallest unit. If you use decimal floating point, you don't need to deal with that.