The initial cost of the station was estimated at $213 million. The City of Chicago and the Chicago Transit Authority were to pay $173 million, and the Mills Corporation (the initial developer) was to pay for the rest. Cost overruns and delays forced the city of Chicago and the Chicago Transit Authority to pay about $100 million to cover already-incurred costs, and the CTA cancelled the project, partly because it did not have the estimated $1.5 billion that would be needed to create express airport service (as opposed to slow local train service using existing tracks and stations). In the end, about $400 million was spent on construction on the shell of a station, plus $40 million in mothballing costs.