I know freshwater has an obscene markup, saltwater livestock not as much. But look at it this way: The retailer has store rent, electricity ( !!!!!!!! ), staffing, maybe a little advertisement, crazy shipping, livestock that dies before its sold, water quality and equipment, man the list must go on and on...
That and the fact that a wholesaler/distributor will NOT accomodate anyone unless they go in there and drop loads of cash on a regular basis (at least, that's supposedly how it is out here). 200-300% doesn't look so insane after all those costs are factored in. Add in a recession/depression, you're looking at one borderline-starving LFS owner.
Not to mention Internet sales of equipment killing the brick n' mortars!