Assuming the buyer of the car that you sold proves that you are legally liable to him or her under certain legal theories of recovery, the measure of damages assuming the judge properly applies the law would be the "lesser" of the costs of repair or the diminution in value of the item sold at the time the transaction was concluded.If you sold the car for $1,350 then it would appear that assuming liability is proven against you, the damages would be the value of the car in the condition that it was sold which could be a lesser amount assuming you failed to disclose all that was wrong with it to the buyer. The $3,000 costs of repairs exceed the price of the car. As such, the $3,000 figure should not be the proper measure under the law.