Upon application therefor, the Commissioner may issue samples of authorized license plates currently issued by the Department. Sample license plates may display, as requested by the applicant and approved by the Commissioner, a combination of up to seven numbers or letters, when feasible. Notwithstanding the provisions of this section, every such license plate shall display the word “SAMPLE” on its face, in a manner prescribed by the Commissioner. The fee for sample license plates not displaying numbers or letters requested by the applicant shall be ten dollars for each license plate. The fee for sample license plates displaying numbers or letters requested by the applicant shall be twenty dollars for each license plate. Sample license plates shall not be valid for registration purposes and shall not be mounted or displayed on any motor vehicle.