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

http://www.cvgairport.com/

Executive Transportation shuttle desks located in baggage claim at CVG, click link to call ahead:  http://executivetransportation.org/Chart.aspx

Dayton International Airport/DAY

http://www.daytonairport.com/