Well you work at a 'better' store. The dedicated 'expert' fish store where i live (we only have one) receives fishes and start selling them 15 minutes later. The chain stores (petco, petsmart, ...) in most places do something similar. I've started to mail order most of my fishes from places that actually do a dedicated qt period before selling.
The last three local purchases i've had fish die and diseases introduced into my established tanks (in a condo and no room for qt tank).
Now that i only mail order fishes - of about 10 orders over the past 2 years - only one 'bad' order in which some (2 of 6) orange laser died the next day (not using that shop again). I've had excellent results from wetspot, tangledcichlid and aquaticclarity. Aquahuna has also been ok for 'cheap' fishes but they have some caveat with very young fishes (small on purchase) and deformities - but they are cheap.
Originally Posted by Dallascowboys16
When I worked at my LFS
we wouldn't let people buy new arrivals for a few days so that they could settle in. Most stores do not do that. Many fish can't handle going straight from shipping to a new tank to another new tank in a matter of 10 hours. I would just ask wherever you are buying your fish from when they got their shipment and if it was more recently than 3 or 4 days I would hold off on purchasing. If the store is in your general area their tanks should have similar parameters if they do a decent job of maintaining the tanks since you both are using the same tap source so I wouldn't pin all of this on the parameters being too different.