तत्र हीनचतुर्गुणो दण्डः ॥ कZ_०२.८.१३ ॥
tatra hīnacaturguṇo daṇḍaḥ
In that case, the penalty is fourfold (of the amount), reduced according to the shortfall/grade.
A gain-based sanction: the fine scales with the magnitude of fiscal harm, discouraging both petty and large-scale manipulation.