Appraiser
An appraiser (from Latin appretiare, “to value”), is one who determines the fair market value of property, real or personal. In England the business of an appraiser is usually combined with that of an auctioneer, while the word itself has a similar meaning to that of “valuer.”
Wikipedia
Appraiser (noun)
One who performs appraisals.
Appraisee (noun)
One who is appraised; one undergoing an appraisal.
Wiktionary