I hate to be a debbie downer, but having worked in the dark bowels of mom and pop LFS on and off for 6 years I would not suggest it as a primary business for anyone, the overbearing majority of LFS aren't really financially viable businesses you can feed your family with, even my favorite LFS only stays open on account of extenuating circumstances personal to the owner I'm not discussing online.
Most of the profit comes from cheap fish, food, chemicals/meds, and feeders. But most drygoods, especially the high end stuff is cost controlled at the distribution level, so you can't charge much more for anything than an online discount store would, and exotic fish are so hard to house longterm that you need to take orders and hope whoever orders anything is able to pick up their fish and pay for it in full when it comes in, you have no idea how many abandoned arowana, big puffers, and rare cichlids we got in that sat in 20s for months before the morons who ordered them could be bothered to pick them up, and even then they'd try to haggle the prices down.
In short I could see it being a nice side business if your spouse is the real breadwinner in the family or if you're independantly wealthy, but the odds are stacked against you no matter where you live on making a living owning an LFS.