Assuming that the policy has comprehensive coverage (not just liability), a first-party claim against his own insurer would be for the fair market value of the car. The insurer would be required to pay the fair market value of the car, measured immediately prior to the accident.
His own insurer would then go after the at-fault driver's insurer to get reimbursed.
You don't get the cost of the repairs you made to your car, but you do get the fair market value of the car. It's as simple as that.