Outrageous parking fees in Chicago

We're planning on a long stay in downtown Chicago the week after next, but we're driving to get there. I just found out that the hotel we're staying in for four nights charges $51 for parking each night, and I don't have the parking fee for the other two nights, but I suspect it will be equally as shocking. We're probably looking at an unexpected $300 in parking fees, which kind of wipes out our shopping budget. Does anyone have some other options? The car will be a rental, so I'm not so attached to it that I'll worry about leaving it somewhere for the week, but it really needs to be kind of secure (we can't really go back and find it missing, after all. We have to get home somehow.)

Thoughts?

When you're parking in downtown chicago, or the downtown area of almost any major city, its going to be expensive, especially when you need to park overnight. $50 a night seems a little on the steep side, but $30 wouldn't be out of the ordinary at all.

The nice thing about Chicago is that it does have a good mass transit system, so you don't have to have a car to get around the city. Your best bet would probably be to simply get a motel in the suburbs (which would be cheaper anyway) and then commute into the city. Alternatively, you could park by the airport (either one) at one of the long term lots that charge $15-20 a day, and take the train in from there.

Or a third option would be to simply drop the car off at the rental agency and see if you can park it there or re-rent a car when you are ready to leave again.