The owner of any such property in order to be exempt from the payment of a registration fee shall provide adequate proof to the Town of the bona fide active marketing of the property for sale by providing such evidence of such bona fide active marketing activities as shall be reasonably required by the Town, including but not limited to, copies of listing agreements and/or pending contracts of sale or other advertising or marketing efforts being made by the property owner directly to promote the sale of the property. Retention of a realtor is not required to actively market a property under this Chapter. Although exempt from the payment of any registration fee, in all other respects, the property owner of any vacant property that is being actively marketed for sale in a bona fide manner shall be required to maintain the property while it is being actively marketed in a bona fide manner in accordance with this Chapter and all other ordinances of the Town of Newton.