They are slightly more expensive on some things, but do have good prices on some stuff too. But any retail location is going to be more expensive when compared to an online resource or big box store. But there is something you get with their store that you will not get other places; Great personal service. Their stock is pretty healthy. And they maintain their tanks well. I don't think I've ever seen a dead fish in there.
They are friendly, knowledgeable, helpful, and will try to talk you out of stuff if they do not think it is a good idea for your tank (over stocking or compatibility issues. And they will explain why). They will go out of their way to help you out and will occasionally give you deals on stuff if you frequent the shop. They can get just about what ever you want if you ask.
Not to mention that you are keeping your money in your community, not adding to the profits of share holders that don't really care about the quality of the service of of the livestock.
They also support the Tropical Fish society of Rhode Island.
The few extra bucks you might spend is well worth it in my opinion.