Hi ,Hobnail was made by Fenton from 1939 into the 1980s Age is a factor, Collectors will pay more for older pieces(1947-1964). some pieces like coin dot were periodically reissued. Identifying post- 1970s pieces is simpler because it was after this decade that Fenton began to mark its pieces. before this Fenton marked its pieces with labels,( so I believe this would date your piece pre 1970) If the original label is present , I believe there are 12 types- which label you have can help you date your item. I would research Fenton makers marks & labels to see if you can date your piece then check for buyers prices in this market.
Hope this helps