Most of the mining is in the north of the state, Sellicks is the last stop south. There is a fair bit of subdivision/ land release, but I don't think there are to many services down there ,ie doctors,shopping centres, Public transport. It used to be mostly old shacks. Great place for a holiday.
Aldinga is growing rapidly which isn't far away from Sellicks, but still a long way from work especially if you work in the city or Nth. , If you wan't to buy Sth have a look at Old Moana, it's more pricey but has limited supply of land and has a great beach . I don't own anything in Sellicks or Old Moana
Cheers Bushy