Prior to the making of an offer to purchase real property for highway purposes by the department, approved values are determined based upon appraisals (including short form appraisals, memorandums of value, or opinions of value) of the real property to be acquired. The approved values used for the final offer are determined based upon a written appraisal by a certified appraiser. The owner or the owner's designated representative is given the opportunity to accompany the appraiser during the inspection of the property being appraised.