St. Clair county switched to the MPSCS digital system. You will need a digital scanner and then program in the control channel and talk groups you want to listen to. Looks like Radio Shack has at least one of the digital scanners for $100 now.
I am pretty sure he did not meen 100 dollars . But if you are looking for a digital scanner someone has a pro 96 on craigslist for $250 in the Detroit area
Doh - you got me excited I thought they were discontinuing something at your local store - I'd take a drive for that... Unless you have one you want to sell for $100...