6. Parents or legal guardians of an unemancipated minor shall be civilly liable for said minor who commits larceny against the property of a mercantile establishment to the operator of such establishment in an amount consisting of:
(a) the retail price of the merchandise if not recovered in merchantable condition up to an amount not to exceed fifteen hundred dollars; plus
(b) a penalty not to exceed the greater of five times the retail price of the merchandise or seventy-five dollars; provided, however, that in no event shall such penalty exceed five hundred dollars.