It's also wise to shun cold calling, mail-order or Internet coin dealers who distribute price guides but then deliver coins graded by substandard certification services without an FTC recommended 15-day return privilege. The Federal Trade Commission has cautioned that some certification services have looser grading standards than the industry norm and warned that coins sold by dishonest coin dealers too often are graded by such companies as "part of fraudulent sales schemes...intended to mislead consumers." Remember price guide prices are typically for PCGS or NGC graded coins and not for grading services whose similar-sounding initials could be confused with PCGS or NGC. Have your dealer repeat each grading service's letters one by one.
But even coins of the same date and grade can trade for higher or lower values between knowledgeable dealers based on a number of eye appeal factors including luster and strike.
Sometimes a buyer will need a particular coin graded by a particular grading service and will pay a premium for that.