Your timing belt is 9 years old and is at 105K miles, right at the mileage recommendation to change out also. Timing belts can fail due to age or wear. You can't tell the difference.
Best reason to change it is because you have an interference engine and failure can cause severe, expensive damage it the belt breaks. That is the best reason to change it now.
No need to pay dealer prices for this repair. Find a good, independent mechanic and get an estimate from him. Changing out the timing belt, water pump, etc at this point sets you up for 105K additional miles. Failing to get it done soon could cause you a far more expensive bill.