Except in an emergency, which the county board shall declare by resolution, no order for delivery on a contract on open market order for personal property or services for any county department or agency shall be awarded until the county clerk is satisfied that the unencumbered balance in the fund concerned, in excess of all unpaid obligations, is sufficient to defray the cost of such order or contract or the county clerk is satisfied that the purchase is one contemplated in the terms of the county budget as set up by the county board. Whenever any officer, office, department, or agency of the county government shall purchase or contract for any personal property or services contrary to the County Purchasing Act, such order or contract shall be void. The county officer or the head of such department or agency shall be personally liable for the costs of such order or contract and, if already paid for out of county funds, the amount may be recovered in the name of the county in an appropriate action.