Depending on your point of origin, it is possible that would be less expensive to fly into Dayton, about an hour north of Cincinnati, though of course with added local costs to Cincinnati.
Cincinnati/Northern Kentucky International Airport/CVG
Link includes overall airport information, including ground transportation
Executive Transportation shuttle desks located in baggage claim at CVG, click link to call ahead: http://executivetransportation.org/Chart.aspx
Dayton International Airport/DAY