The Bayside area is generally more expensive because of it is proximity to Brisbane.
Bribie Island has three distinct areas.
Woorim on the east, with beautiful surf beaches and the national park. Ideal for camping and beach driving.
Bongaree/Bellara on the west side, opposite the mainland, that adjoins the calm Pummistone Passage. Ideal for all water sports and fishing.
Banksia Beach with its Pacific Harbour and Golf complex. New purpose built homes around canals and excellent golf complex.
Hope this helps.