Hey Dingo Mango,
I interviewed waaaay back in October and stayed at the Courtyard Marriott hotel:
http://www.marriott.com/hotels/travel/chiwk-courtyard-chicago-waukegan-gurnee/
If you use the discount code from the RF e-mail about accommodations, it should only be about $99. It's still a little pricey, but the room was truly fantastic, the free breakfast was perfect, and the shuttle to CMS was great. There's a Denny's and a Wal-Mart 1 minute walking distance from the hotel. I remember talking to a couple of other interviewees who stayed there and we all agreed that it was great!!
As far as transportation is concerned, you'll need to get a cab to take you to the hotel in Waukegan, which is about 30-45 minutes north of O'Hare. If I recall correctly, I used the suggested cab transport provided by CMS in their interview invite confirmation e-mail. It was $45. On your way back from CMS to O'Hare, I would recommend splitting a cab between you and other interviewees. That's what I did and it saved me some dough. I just asked the other interviewees during the break if they were heading to O'Hare after and we just grouped up. Make cab reservations so that you don't miss your flight.
I really liked this school and it was an awesome interview day. Good luck!
(On a side note, I don't think that interviewing certain applicants is a waste. There is a reason why a school decides to bring them out to visit and a reason why the student chooses to go. Those reasons are different for every school/student. I know plenty of people who turned down top schools that they wanted to go to (pre-superstressedfromapplyingtomedschool) for schools with not as great a reputation because they found something that they truly liked about it before the interview day, and ended up loving it and myriads of other things during the interview day. It's like a first date. You come to the date knowing little about the person (heck, you probably have some bias already based on what other people have said), but anything can happen and you can end up together. And if it doesn't work out, then someone else who has been eying this girl/guy can get his/her shot. The most that person has to do is wait
😳 Anyways, sorry for the rant [and the metaphor; I've been watching way too much of HIMYM). I wish you all the best of luck!!!)