Aquarium and Reef Center may be overpriced compared to your online shopping or, mikes corals fish and rock, but they also don't have quite the overhead.
Mike's shop isn't very large and last I heard he doesn't have any overhead at all.
All The online shops around here don't have any at all considering they buy in bulk, or they usually have the items shipped from the suppliers to the customers (cuts out some of the middle man).
You have to take into consideration the information and time the Aquarium shops are willing to put into teaching fundamentals, helping you with problems, sweating in a shop six days a week, going to Miami or Tampa to handpick livestock, and maintaining everything in a shop downtown Cape Coral/Del Prado.
They have one of the nicest shops around with a very high standard and variety of livestock and along with that comes price inflation.
Thats my opinion on the whole subject.