They are not difficult to keep as long as they are given the conditions they like the most. I have a special love for these corals and are my top favorite in the hobby. I have dozen in the current tank. Po4 not higher then 0,7-1 and no3 around 5-10 not much flow. This works best in my experience in all the years I am in the hobby..
The reason as to why they expensive is because there been en export ban for long time, that’s comming to a end slow by little.. so you see more on the market these days.. that’s from Indonesia. Australia has a import ban stil.
Also they can’t be fragged, they just grow bigger in size. This 2 of the major reasons of there high cost rate. They have extreme beautiful colors and that’s making them very wanted for collector’s.. because that’s what they are to me: collector items.