I rotated here (finishing up intern year here at Mayo) as a student and I'd agree with Bone_Jock. If you happen to know somebody then maybe live with them, but otherwise the Kahler is the way to go. With the student discount it works out to be around 100 bucks a week. Literally one crosswalk from Methodist, and just as close to the shuttle stop to go to St. Mary's (which usually runs early enough in the morning, although sometimes after a late OR night at St. Mary's you'll need to hitch a ride or walk). Not really luxury living, just a typical hotel room with a TV, small fridge in the room, and they have a student "lounge" with a microwave, kitchen, etc whenever you need it.
Parking can be a problem if you're staying at the Kahler (I flew up and didn't bring a car), because I think they charge you a pretty decent fee to park in their lot (I wanna say 7 bucks a day or 70 a week, I can't remember ???). There are places to park off campus and take a shuttle into town if you want, there really isn't that much need for your car during the week anyway (although on the weekends it would have been nice). Most places during the week you can bum a ride with one of us, and then just get your car if you need it on the weekend, or don't bring a car at all.
It's a pretty laid back rotation for students, you usually spend 2 weeks with one consultant and 2 weeks with another. Most students don't get assigned to OTS, although it does happen. You're more than welcome to come take a call if you want (I'll be one of the OTS 2's first quarter if you're coming up between July and first of October), just let one of us know when you get here. Don't feel any pressure to do so though, I took zero call when I was up here. I do think Bone_Jock is right that it's a good way to see OTS first hand (ie prove to yourself that we actually do operate, and there actually is more than enough trauma here).
I sent you a message, just let me know if you have any other questions..