The term 'Cost of Doing Business' refers to the expenses associated with running a business. This includes things such as labor costs, taxes, and overhead. The two crossword solutions for this term are 'FEE' (3 letters) and 'FEES' (4 letters). 'FEE' is a singular noun that refers to a fixed charge for a service or privilege, while 'fees' is the plural form of the same word. Both words refer to the money that a business must pay in order to operate.