Money type is discouraged as described here
My application needs to store currency, which datatype shall I be using? Numeric, Money or FLOAT?
Practice As Follows
Numeric with forced 2 units precision. Never use float or float like datatype to represent currency because if you do, people are going to be unhappy when the financial report’s bottom line figure is incorrect by + or – a few dollars.
The money type is just left in for historical reasons as far as I can tell.