A person may not distribute Salvia divinorum to an individual under the age of 21 years. In a prosecution for a violation of this section, it is a defense that the defendant examined the purchaser’s or recipient’s driver’s license or other valid identification issued by an employer, a government unit, or an institution of higher education that positively identified the purchaser or recipient as at least 21 years of age. A person who violates this section is guilty of a misdemeanor and on conviction is subject to a fine not exceeding: $1,000 for a first violation; $2,000 for a second violation occurring within 2 years after the first violation; and $6,000 for each subsequent violation occurring within 2 years after the preceding violation. For purposes of this section, each separate incident at a different time and occasion is a separate violation.