These came from the Margaret River area of Western Australia. The most expensive one is a lower two crown one about one metre tall and is for sale for about $4,460. A taller one with three crowns about two metres tall is cheaper at $4,300.
Most varieties are quite resistant to fire and as you can see in their natural state in the first photo taken by Matthew Newton and published on the website of Bush Heritage Australia, they retain their lower dried up spines and in the case of fire, like with our Eucalypts, the fire will race up to the top of the plant and give some protection to the trunk. Most of the growing action takes place underground and this also helps them resist fire.
However, I would not be spending thousands on such plants when some brief research tells me they are notoriously difficult to transplant from one site to another.
They grow in a gorge west of Sydney and their location is not publicised as visitors could be a terrible threat to their existence of one of the rarest trees on Earth, numbering somewhat over 100. They have been successfully propagated and you can buy them at plant nurseries. Some trees are estimated to be 1,000 years old but because of the nature of they way the grow, they could be very much older. Photo from the Sydney Morning Herald.