Change brings suffering - Buddha
I live in the DC metro area and I get almost all my fish online from user-certified vendors or from CCA members. Anything from a retail outlet has to be something I really want and has to pass the "eyeball test", that is, looks good, isn't stuffed into an overcrowded or dirty tank, doesn't have wonky or dead specimens as tank-mates, etc. Even then they get their own tank for a couple weeks to try and ensure that they don't introduce something weird into my other tanks.
My own concerns about origin are aimed at a personal preference for captive bred stock - can't say whether that increases or decreases the risk of disease, but I tend toward thinking that sick fish come from sickly conditions, and like humans are routinely exposed to lots of things that can make them ill that they/we can ordinarily resist unless our immune systems get compromised, hence the rigorous application of the eyeball test in a place where fish are often as or more stressed than they will be at any other point in their lives. Just the nature of change.
First fish I bought 3 years ago when I moved to DC and returned to fishkeeping were some red-hump Geophagus at a Petco or Petsmart. They live at the neighbors house now but live they do. The second were a pair of Wild adult Bolivian rams that will probably die of old age. Opinions doubtless vary, but if a fish looks/acts healthy, my experience is that it generally is.
The coolest thing about the LFS scenario for me is that you never know what you're going to find and there's just not really any better means of assessing a "new" species than to get to look at it. The surprises become fewer and farther apart over time, but the possibility always remains. Good hunting.
