The Commission to study consolidation has recently completed a series of listening hearings around the state to gather information regarding consolidation. They have studied the costs if districts were to consolidate. The attached report provides interesting readable information.
http://www2.illinois.gov/ltgov/Documents/CFC%20Materials/December%205,%202011%20Meeting/ISBE%20Presentation%20on%20Multi-District%20Realignment.pdf