It's like everything else these days. Any hobby supply shop. You get people interested in Widgets. You go to the widget store. Then you go home and buy it online for half the price. It's not that the Widget store is overpriced, its that they have overhead so you can go inspect said widget, and find other people interested in widgets. My LFS, I buy something everytime I go in. Whether it's food, or a part. Places like petsmart, will be around, they're the walmart of this hobby. You want real info, with unique fish etc, You need a mom and pop store. It's not enough to just buy your fish from them. That won't pay the bills. You needs to pay retail for some items to keep their doors open.
Find the right LFS for you. Spend some money there, try and always buy something. Invest in them, and they'll invest in you. When you say you've been looking everywhere for that 7 eye'd clown loach. You'll be the first person they mention when someone brings one in.
The other things you can do, when you do buy something from a mom and pop store, try to use cash. They lose up to 5% of the sale by you just using your debit/credit card.