Fish stores are pretty sketchy in Las Vegas simply due to issues getting good specimens into the valley. With that said, Atlantis usually maintains a good selection and most times has some room to negotiate. Their supplies are not over the top expensive as some of the their competitors and their staff is young, hip, and pretty knowledgeable.
We usually swing by once a month as it is a good haul from where we live.
They have a decent SW selection and usually stock some cheap tanks as well.
If you are a fishkeeper Atlantis is worth the drive to check it out.