Per Books Online (BOL):

"Only constants and @local_variables can be passed to table-valued functions."

"The value of each declared parameter must be supplied by the user when the function is executed."

This means that the parameters (@Freight_min money, @Freight_max money) can be a variable or a constant, but cannot be a per row value as the parameters are evaluated when executed.

Example:

SELECT * FROM LargeOrderShippers(500,1000)

DECLARE @Freight_min money, @Freight_max money

SELECT @Freight_min money = 500, @Freight_max money = 1000

SELECT * FROM LargeOrderShippers(@Freight_min, @Freight_max)

Andy