05 saab 9-3 linear sport sedan

recently purchased two weeks ago, clock was flashing 12:00(note). shortly after leaving the dealer within 10 miles I stopped for a quick lunch, went out to start car and in the process goes through the check mode. this is the first time i encountered the ” stability control failure” message in the info center. I cleared the message and went on my way. Two days later this comes up on the info center and now stays. putting two and two together the dealer cleared the code by disconnecting the battery and resetting. ok, so took it to a shop to read the code and the general description is related to the YAW SENSOR. Curious how big of a project this can turn into if it is a sensor? The ABS works but the ESP now does not, but did when I test drove it. The dealer is willing to cover some of the cost for the repair to a certain point or my other option is give the car back for my trade or refund. In your professional opinion does this sound like an expensive fix? Thanks