Considering building in Thirroul or Austinmer. Are there blocks and what is the average price?

Few blocks for sale,getting very expensive. $700k for 500m2 . Several people buy properties to knock down and rebuild ,$1.2m for 700m2 knock down rebuild on Point Street for example, where I can see several single level units /houses ,which are being rebuilt as double storey houses close to the beach.