I've noticed their prices are good if you know what you're looking for. A FEW fish are overpriced, but their selection is truly unique. I strongly suggest you go.
The "empty tank" thing is because they do sell out very fast, really.
It is true, they don't order A LOT of fish, but this is in fact good, as the fish have plenty of space.
Have not had any trouble at all with this store.
Their employees are evidently worn out, but still one of the best stores in Mass.