The silver certificates issued in 1928 were a smaller size than those that had been previously issued. The next issue of silver currency was in 1934, so I will assume that yours is the 1928 issue. A series 1928 $1.00 note can bring anywhere from $6.00 to $60.00 depending on the condition. As you say it is "fair", that would be at the lower end of the price range. You can research this further by consulting "Bank Note Reporter," Krause Publications, usually available at your local book store.
http://www.rrcoins.net/Q&A.htm (Question 9)