Overpriced is relative though. It definitely costs more than the others, sure.
But if you place a high value on hot girls perhaps it is more fairly priced for one person as compared to another? If you don't then yeah, it would be a waste of money. You would be better off at Barra or Playmates.
Luna Lunera seem to be the one of those five that is definitely "overpriced." Meaning it is not much cheaper than La Isla or Fase II but the quality is lower, and even the service staff are pushy, upselling, etc. The worst of both worlds.
Like most things, it depends on what you are looking for.