Moorish idols are very difficult to keep. They need special care in regards to the diet etc. QT is a must IMO, that with all fish but especially these. Live foods on hand when they arrive as well as offering nori daily.
I just received two last week, they both ate frozen on the first day. Mine came from online.
I also think that the location collection plays a large roll in the long term success.
My first choice is Maldives, the only other place I would order from is Hawaii.