are [GolfSingle] and [GolfFour] columns? Or are they calcualtions?
you cant use calculations names in a calcualtion. you would need to use the calcualation itselct in place of the name, so if
GolfSingle is the name of the calculation defined as:
[RegGolfSingle]*75
you would use the definition in the total price calcualtion:
([Price] + ([RegGolfSingle]*75) + ([RegGolfFour]*275)) * [Quantity]