Any person who has been convicted of violating the provisions of § 18.2-103 shall be civilly liable to the owner for the retail value of any goods and merchandise illegally converted and not recovered by the owner, and for all costs incurred in prosecuting such person under the provisions of § 18.2-103. Such costs shall be limited to actual expenses, including the base wage of one employee acting as a witness for the Commonwealth and suit costs. Provided, however, the total amount of allowable costs granted hereunder shall not exceed $250, excluding the retail value of the goods and merchandise.