I know what you mean about LFS. I always say that I will never buy anything "live" from a certain store here in my home town. But that is where I got my tomato clown from. Full of ich etc. I am very happy to say that I saved this poor thing and it is doing just great, very healthy now.
But when they have their 2 for 1 it is hard to resist but I have to now as salt water costs just to much to take the risk of bringing anything into your aquarium. So no more fish from there for me. We have a great marine store here that has excellent fish, corals etc. That is where I buy from now.
A lesson learned from me the hard way when I stocked my freshwater tank from that LFS and had all but 3 die in a tank that has been up and running for the past 10 years.
Good luck to you and be really picky where you buy your fish from.