For a moderately priced seafood buffet the Cape May Cafe in the Beach Club is your best bet. They serve steamed clams (ind garlic broth or plain), fish, mussels, clams, chicken, ribs, mashed potatos, boiled potatos, steamed veggies, carving station, breads, chowders and lots of salads and desserts.
Flying Fish on the Boardwalk has excellent seafood but is a bit pricey.
Fultons is good too, but the service can be iffy and it is also pricey.