Its hit and miss with ordering fish online. Usually long as you pick reputable sellers its a non-issue. I also avoid the big commercial sites like liveaquaria as I've never heard anything good about their quality compared to a regular shop. For me to order online it needs to be either too difficult or expensive to get locally. I'm usually looking for harder to find things when I am ordering online since I have a pretty great selection locally. That or I am ordering A LOT. I generally stick to much smaller importers that specialize in uncommon fish. Yes shipping is expensive. Some species can survive priority shipping, but any thing non-hardy or a large shipment should go express which isn't cheap unless you are making up for it in quantity. I still have some wild caught fish I ordered online like 4-5 years ago.