Aquarium Concepts is a joke, I hate that place. Their fish are sick as often than not, their advice can range from decent, to so-so, to absolute bull, often I have to id fish for them when I am asking about them, and then they don't even care. The only thing going for them is a huge selection and decent prices.
Tropical Paradise is much more dependable, imo - and for reefkeepers it is a #1 destination. Eddie always has mantis' in there for sale, last time I was in he had four - from $19-$29. If he is charging $29, believe me it is probably worth it.
Personable management is what you want to look for in the long run in this hobby, I am always happier to give my money to honest people.