Who's selling one for 500? Here they are free on cultured live rock. The one I have was collected on a night dive, I usually see one or two per dive on night dives. They are not uncommon, but they don't open during the daylight (at least the native ones) and that makes them undesirable in tanks. As colorful as mine is I don't collect any more because during the day when lights are on in my tank it looks like a reddish brown closed up anemone.