(1) A violation of section 28-526 shall be a:

(a) Class IIA felony when the aggregated retail market value of the retail merchandise involved is five thousand dollars or more;

(b) Class IV felony when the aggregated retail market value of the retail merchandise involved is one thousand five hundred dollars or more but less than five thousand dollars; and

(c) Class I misdemeanor when the aggregated retail market value of the retail merchandise involved is more than five hundred dollars but less than one thousand five hundred dollars.

(2) A second or subsequent conviction under subdivision (1)(c) of this section shall be a Class IV felony.

(3) For a prior conviction to be used to enhance the penalty under subsection (2) of this section, the prior conviction must have occurred no more than ten years prior to the date of commission of the current offense.

(4) The aggregated retail market value of amounts taken pursuant to one organized retail crime scheme from one or more persons may be aggregated in the same indictment, information, or complaint in determining the classification of the offense, except that amounts shall not be aggregated into more than one offense.

(5) In any prosecution of a violation of section 28-526, aggregated retail market value shall be an essential element of the offense that must be proved beyond a reasonable doubt.