You can actually use Uber at Midway if you set the ping just outside the airport. When the call tell them you are at the airport and they'll pick you up.
Have you checked some offsite independent parking lots? There are several that service Midway. My mother uses one in particular (the name currently escapes me). Unless you live very close to the airport, taxi/limo fees are going to add up quickly.
Sometime Groupon has limo deals. Of course, the cost depends on where you're coming/going to. For us it still makes sense to pay to park, but we come from way up north.
Not sure where you would be coming from but my sister took a bus this past winter. She said it was really convenient, the driver was very professional and the bus was clean so I plan to use it this fall. http://www.coachusa.com/
A 3 person limo from the Schaumburg area costs around $90 (with tip) each way. You can use Park and Fly on 47th street for around $10/day. They shuttle you to and from the airport.
A 3 person limo from the Schaumburg area costs around $90 (with tip) each way. You can use Park and Fly on 47th street for around $10/day. They shuttle you to and from the airport.