I live the upper peninsula of MI. I am looking for a place to do a necropsy on a chicken for a reasonable price.
Iron County Michigan
The cheapest would be to do it yourself, and if you have any familiarity with chicken organs a lot of times the ailment is fairly easy to spot. If you aren't comfortable doing it yourself you can send them into the MSU Veterinary Diagnostic lab in East Lansing. Their phone number is 517-353-3045.