saved money, headaches-bids for foundation work,one combined price, including both excavation and concrete. each concrete subcontractor gets price from his favorite excavator,submits one price. you won’t be faced with extra charges by form setters for extra work on a hole not to their liking eliminating surprise extras. this strategyresults in one less subcontract to let,schedule, supervise shuffle avoiding conflict between 2 subcontractors you in the middle.Douglass Ferrell