The court shall limit the scope of a forfeiture judgment issued pursuant to section [712A-5(1)(b)] to the extent the court finds the effect of the forfeiture is grossly disproportionate to the nature and severity of the owner's conduct. In determining whether a forfeiture is grossly disproportionate, the court may consider:
(1) The degree to which the property was used to facilitate the conduct that subjects property to forfeiture and the importance of the property to the conduct;
(2) The gain received or expected by an owner from the conduct that subjects property to forfeiture and the value of the property subject to forfeiture;
(3) The nature and extent of the owner's culpability; and
(4) The owner's effort to prevent the conduct or assist in prosecution.