I have never relied on fish stores for almost anything.
Also, if I need to find something rare or unusual I can always rely on somebody in my fish club to know the answer to finding it. A lot of the time our guest speaker on a species can help with that. What I do know is it is not all that uncommon at my fish club meeting for some new and/or hard to find species turn up.
I have met a number of folks who travel the world to find fish. These folks often turn up a weekend events.
It is important to remember that fish stores exist to make money for the owner. This means many, but not all of them, will only do what they them is worthwhile for them.
A lot of us forget that most of the people who keep fish have just a single tank which they care for because they like to watch the fish. They do not care about endangered species or having rare fish. Some may end up with a 2nd or third tank over time but this makes them happy. Then their are the fish nuts who get very involved with things, and they want rarer fish and more tanks.
The farther outside a dense urban area in which one lives, the less likely it is to have a sophisticate shop which can and does get in the really neat stuff some of us may want.