I've had a feeling that it was a wiring problem all along becasue of the nature of how your car was acting prior to its complete failures. The PCM wouldn't do that, it would just die all of a sudden, not just little things here and then having problems.
I want to that it is very possible that what ever problem there is may have shorted out wires that has casued the PCM to fail or burn out becasue of the short. But if there is short or other problem that led to the failure of the PCM then what ever they put in wether new or used replacement its reasonable for me to believe that the one they install will also fry. IF you go the route of having them replace the PCM make sure that you get in writing, on dealership letterhead signed by the general manager and the service manager that if they replace the PCM for troubleshooting pourposes and the replacement fails due to what ever problem there is you will receive another replacement at no cost to you what so ever including both parts and labor.
The reaosn I am confident that it may be a wiring problem is becasue I remember something publication from FORD, wether a TSB or recall for wiring harnesses on Contours up to a certain model year had a problem of the wiring insulation degrading and failing over time due to a poor insulation material. If this was a recall and your car was part of it, has not been accomplished yet and the recall is still active you may be able to get the harness replaced for free under the recall, and you could go as far as to say that the PCM failed due to the faulty harness and be able to get all of this fixed at no cost..... But, I'll say it again, But all this hinges on (1) I am corect, which I am not sure of and (2) wether there was actually a recall and if so, wether it was performed or not and if it is still active.
I feel sorry for the people who don't drink. When they wake up in the morning, thats the best they're going to feel all day - former President Lyndon B. Johnson
