You could actually contact a taxi company that will pick you up. American Taxi Company I believe has a flat rate from the airport. I think it is somewhere on the lines of 45 dollars. Here is the website. http://www.americantaxi.com/rates.asp
You can contact them and arrange a pick up. The 75-80 dollar price is the metered price from O'Hare to the suburbs. You definitely wanna go with this company since they have a flat rate. I myself used this company when I interviewed at Scholl last year. BTW... from Midway to North Chicago using this company is 69 bucks. Another option is to catch the train from the airport. I believe that is like 5 dollars. Don't quote me on that one. Goodluck on your interview!