There is no one-size-fits-all answer to this question, as the cost of private investigation services can vary greatly depending on the specific case and needs of the client. However, in general, most private investigators will charge an hourly rate for their services, which can range from $50 to $200 per hour. In addition to this hourly rate, some investigators may also charge a flat fee for certain services, such as background checks or surveillance. Ultimately, the total cost of a private investigator will depend on the scope and complexity of the case being investigated.