Chicago-area real-estate investor John Cooper closed on the home, named Champions Point, at the beginning of December, buying it for $9.5 million, records show. He got a steep discount for the Highland Park mansion, which was initially asking $29 million when it was first listed in 2012, Mansion Global previously reported .

The co-ownership shares give buyers a week of access to the property each year, including an option to host events there for an extra fee.