I may be stating the obvious, or someone may have a more clever way to do this, but I find it's helpful to call several parking ramps before I arrive in Chicago. Because using Priceline means you'll often stay at different hotels each time you go, it helps to have a plan before you arrive.
I use the handy-dandy Chicago Parking Map link (www.chicagoparkingmap.com
) to see all the private parking lots and ramps in downtown Chicago. I zoom in on the area around my hotel. The maps are nicely marked and have the hotels listed. You'll see a blue "P" for parking lots/ramps. If you click on the "P" you will see very general information about the ramp like the number of spaces and a telephone number for the ramp attendant/owner.
I then call the ramp and ask what their rates are for a 24 hour period for a weekday. (If you are coming in after 4:00 or so on Friday afternoon, I'd ask them if they have weekend rates and what time they are applicable.) On a recent visit to the Intercontinental on Michigan Avenue on a Thursday night, I found rates for private ramps ranging from $22 to $28 for a 24 hour period. (The hotel rate was almost $50.) So you see that it's helpful to call a few places, find the cheapest rate, and map out a plan for your arrival.
By the way, if you aren't from a big city, know that you will spend big bucks to park in ramps for less than 24 hours. Most ramps make you pay the 24 hour rate starting at 8-10 hours. They'll make you pay something like $6/$9 for the first hour, then $15 or something for up to 3-4 hours, then $20 or something for 4-8 hours, then the ful daily rate for over 8 hours and up to 24 hours. Then at the 24 hour mark, the clock starts all over again. Goody! (My examples above are fictitious, since I'm not from Chicago and don't park there often enough to give you a good example. But as a small city gal, I wasn't aware of the outrageous rates they charge for such small amounts of time!)