I have purchased around 30 or so. Some move, some don’t. Not really a huge issue with them stinging other corals. They are pretty easy to care for and are certainly beautiful! Especially under the blues in the evening time. You could make your tank look like a scene from Avatar if you bought enough of them. It pays to shop around though.
I’ve found the least expensive place to purchase them is salt critters. What irritates me is when a beautiful specimen decides to hide on the back side of the rock work!! I wish they would all stay put!!! It’s really hard to color coordinate things when your painters pallet is moving around!!! Lol!! I’ve found they’re more likely to stay put if placed on a rock that has a small hole where they can place their foot. That and feeding them encourages them to stay put. Seems i was reading somewhere a lot of the brightly colored ones are collected from deeper waters. So they don’t really need a whole lot of light.